Let meca use -C for cpt like the rest of GMT (#4873)

* Let meca use -C for cpt like the rest of GMT

See #4869 for context. In the process we also needed to move -C to -A.  This was all done with backwards compatibility in mind.

* Default is no circle at end of line

Consistent with GMT4

* Only draw circle if diameter is nonzero

* Update psmeca.c

doc/rst/source/supplements/seis/explain_meca_-S.rst_

@@ -32,7 +32,7 @@
     magnitude
 
     **8**,\ **9**:
-    longitude, latitude at which to place beachball if **-C** is used (optional).
+    longitude, latitude at which to place beachball if **-A** is used (optional).
     Using 0,0 in columns 8 and 9 will plot the beach ball at the longitude,
     latitude given in columns 1 and 2. The **-:** option will interchange the order of
     columns (1,2) and (8,9).
@@ -60,7 +60,7 @@
     mantissa and exponent of moment in dyne-cm
 
     **12**,\ **13**:
-    longitude, latitude at which to place beachball if **-C** is used (optional).
+    longitude, latitude at which to place beachball if **-A** is used (optional).
     Using 0,0 in columns 12 and 13 will plot the beach ball at the longitude,
     latitude given in columns 1 and 2. The **-:** option will interchange the order of
     columns (1,2) and (12,13).
@@ -90,7 +90,7 @@
     exponent
 
     **11**,\ **12**:
-    longitude, latitude at which to place beachball if **-C** is used (optional).
+    longitude, latitude at which to place beachball if **-A** is used (optional).
     Using 0,0 in columns 11 and 12 will plot the beach ball at the longitude,
     latitude given in columns 1 and 2. The **-:** option will interchange the order of
     columns (1,2) and (11,12).
@@ -121,7 +121,7 @@
     magnitude
 
     **9**,\ **10**:
-    longitude, latitude at which to place beachball if **-C** is used (optional).
+    longitude, latitude at which to place beachball if **-A** is used (optional).
     Using 0,0 in columns 9 and 10 will plot the beach ball at the longitude,
     latitude given in columns 1 and 2. The **-:** option will interchange the order of
     columns (1,2) and (9,10).
@@ -149,7 +149,7 @@
     exponent
 
     **14**,\ **15**:
-    longitude, latitude at which to place beachball if **-C** is used (optional).
+    longitude, latitude at which to place beachball if **-A** is used (optional).
     Using 0,0 in columns 14 and 15 will plot the beach ball at the longitude,
     latitude given in columns 1 and 2. The **-:** option will interchange the order of
     columns (1,2) and (14,15).

doc/rst/source/supplements/seis/meca.rst

@@ -12,12 +12,18 @@ Synopsis
 
 .. include:: ../../common_SYN_OPTs.rst_
 
-**gmt meca** [ *table* ] |-J|\ *parameters* |SYN_OPT-R|
+**gmt meca** [ *table* ]
+|-J|\ *parameters*
+|SYN_OPT-R|
 |-S|\ *<format><scale>*\ [**+a**\ *angle*][**+f**\ *font*][**+j**\ *justify*][**+o**\ *dx*\ [/*dy*]]
+[ |-A|\ [**+p**\ *pen*][**+s**\ *size*] ]
 [ |SYN_OPT-B| ]
-[ |-C|\ [*pen*][**+s**\ *size*] ] [ |-D|\ *depmin*/*depmax* ]
+[ |-C|\ *cpt*]
+[ |-D|\ *depmin*/*depmax* ]
 [ |-E|\ *fill*]
-[ |-F|\ *mode*\ [*args*] ] [ |-G|\ *fill*] [ |-L|\ [*pen*] ]
+[ |-F|\ *mode*\ [*args*] ]
+[ |-G|\ *fill*]
+[ |-L|\ [*pen*] ]
 [ |-M| ]
 [ |-N| ]
 [ |-T|\ *nplane*\ [/*pen*] ]
@@ -26,7 +32,6 @@ Synopsis
 [ |-W|\ *pen* ]
 [ |SYN_OPT-X| ]
 [ |SYN_OPT-Y| ]
-[ |-Z|\ *cpt*]
 [ |SYN_OPT-di| ]
 [ |SYN_OPT-e| ]
 [ |SYN_OPT-h| ]

doc/rst/source/supplements/seis/meca_common.rst_

@@ -29,19 +29,26 @@ Required Arguments
 Optional Arguments
 ------------------
 
+.. _-A:
+
+**-A**\ [**+p**\ *pen*][**+s**\ *size*]
+    Offsets focal mechanisms to the alternate longitudes, latitudes given
+    in the last two columns of the input file before the (optional) text
+    string. We will draw a line connecting the original and relocated
+    beachball positions and optionally place a small circle at the original
+    location.  Use **+s**\ *size* to set the diameter of the circle [no circle].
+    The line pen defaults to that given via **-W** but can be overridden
+    by using **+p**\ *pen* [0.25p].
+
 .. _-B:
 
 .. include:: ../../explain_-B.rst_
 
 .. _-C:
 
-**-C**\ [*pen*][**+s**\ *size*]
-    Offsets focal mechanisms to the longitude, latitude specified in the
-    last two columns of the input file before the (optional) text
-    string. A small circle is plotted at the initial location and a line
-    connects the beachball to the circle. Specify *pen* and optionally append
-    **+s**\ *size* to change the line style and/or size of the circle.
-    [Defaults: *pen* as given by **-W**; *size* is 0].
+**-C**\ *cpt*
+    Give a CPT and let compressive part color be
+    determined by the z-value in the third column.
 
 .. _-D:
 
@@ -146,12 +153,6 @@ Optional Arguments
 
 .. include:: ../../explain_-XY.rst_
 
-.. _-Z:
-
-**-Z**\ *cpt*
-    Give a CPT and let compressive part color be
-    determined by the z-value in the third column.
-
 .. |Add_-di| unicode:: 0x20 .. just an invisible code
 .. include:: ../../explain_-di.rst_
 

doc/rst/source/supplements/seis/psmeca.rst

@@ -12,21 +12,29 @@ Synopsis
 
 .. include:: ../../common_SYN_OPTs.rst_
 
-**gmt psmeca** [ *table* ] |-J|\ *parameters* |SYN_OPT-R|
+**gmt psmeca** [ *table* ]
+|-J|\ *parameters*
+|SYN_OPT-R|
 |-S|\ *<format><scale>*\ [**+a**\ *angle*][**+f**\ *font*][**+j**\ *justify*][**+o**\ *dx*\ [/*dy*]]
+[ |-A|\ [**+p**\ *pen*][**+s**\ *size*] ]
 [ |SYN_OPT-B| ]
-[ |-C|\ [*pen*][**+s**\ *size*] ] [ |-D|\ *depmin*/*depmax* ]
+[ |-C|\ *cpt*]
+[ |-D|\ *depmin*/*depmax* ]
 [ |-E|\ *fill*]
-[ |-F|\ *mode*\ [*args*] ] [ |-G|\ *fill*] [ |-K| ] [ |-L|\ [*pen*] ]
+[ |-F|\ *mode*\ [*args*] ]
+[ |-G|\ *fill*]
+[ |-K| ]
+[ |-L|\ [*pen*] ]
 [ |-M| ]
-[ |-N| ] [ |-O| ] [ |-P| ]
+[ |-N| ]
+[ |-O| ]
+[ |-P| ]
 [ |-T|\ *nplane*\ [*pen*] ]
 [ |SYN_OPT-U| ]
 [ |SYN_OPT-V| ]
 [ |-W|\ *pen* ]
 [ |SYN_OPT-X| ]
 [ |SYN_OPT-Y| ]
-[ |-Z|\ *cpt*]
 [ |SYN_OPT-di| ]
 [ |SYN_OPT-e| ]
 [ |SYN_OPT-h| ]