remove some deprecated Doxyfile.in settings

docs/Doxyfile.in

@@ -93,14 +93,6 @@ ALLOW_UNICODE_NAMES    = NO
 
 OUTPUT_LANGUAGE        = English
 
-# The OUTPUT_TEXT_DIRECTION tag is used to specify the direction in which all
-# documentation generated by doxygen is written. Doxygen will use this
-# information to generate all generated output in the proper direction.
-# Possible values are: None, LTR, RTL and Context.
-# The default value is: None.
-
-OUTPUT_TEXT_DIRECTION  = None
-
 # If the BRIEF_MEMBER_DESC tag is set to YES, doxygen will include brief member
 # descriptions after the members that are listed in the file and class
 # documentation (similar to Javadoc). Set to NO to disable this.
@@ -1111,44 +1103,6 @@ USE_HTAGS              = NO
 
 VERBATIM_HEADERS       = YES
 
-# If the CLANG_ASSISTED_PARSING tag is set to YES then doxygen will use the
-# clang parser (see:
-# http://clang.llvm.org/) for more accurate parsing at the cost of reduced
-# performance. This can be particularly helpful with template rich C++ code for
-# which doxygen's built-in parser lacks the necessary type information.
-# Note: The availability of this option depends on whether or not doxygen was
-# generated with the -Duse_libclang=ON option for CMake.
-# The default value is: NO.
-
-CLANG_ASSISTED_PARSING = NO
-
-# If clang assisted parsing is enabled and the CLANG_ADD_INC_PATHS tag is set to
-# YES then doxygen will add the directory of each input to the include path.
-# The default value is: YES.
-
-CLANG_ADD_INC_PATHS    = YES
-
-# If clang assisted parsing is enabled you can provide the compiler with command
-# line options that you would normally use when invoking the compiler. Note that
-# the include paths will already be set by doxygen for the files and directories
-# specified with INPUT and INCLUDE_PATH.
-# This tag requires that the tag CLANG_ASSISTED_PARSING is set to YES.
-
-CLANG_OPTIONS          =
-
-# If clang assisted parsing is enabled you can provide the clang parser with the
-# path to the directory containing a file called compile_commands.json. This
-# file is the compilation database (see:
-# http://clang.llvm.org/docs/HowToSetupToolingForLLVM.html) containing the
-# options used when the source files were built. This is equivalent to
-# specifying the -p option to a clang tool, such as clang-check. These options
-# will then be passed to the parser. Any options specified with CLANG_OPTIONS
-# will be added as well.
-# Note: The availability of this option depends on whether or not doxygen was
-# generated with the -Duse_libclang=ON option for CMake.
-
-CLANG_DATABASE_PATH    =
-
 #---------------------------------------------------------------------------
 # Configuration options related to the alphabetical class index
 #---------------------------------------------------------------------------
@@ -1590,17 +1544,6 @@ HTML_FORMULA_FORMAT    = png
 
 FORMULA_FONTSIZE       = 10
 
-# Use the FORMULA_TRANSPARENT tag to determine whether or not the images
-# generated for formulas are transparent PNGs. Transparent PNGs are not
-# supported properly for IE 6.0, but are supported on all modern browsers.
-#
-# Note that when changing this option you need to delete any form_*.png files in
-# the HTML output directory before the changes have effect.
-# The default value is: YES.
-# This tag requires that the tag GENERATE_HTML is set to YES.
-
-FORMULA_TRANSPARENT    = YES
-
 # The FORMULA_MACROFILE can contain LaTeX \newcommand and \renewcommand commands
 # to create new LaTeX commands to be used in formulas as building blocks. See
 # the section "Including formulas" for details.
@@ -1904,16 +1847,6 @@ LATEX_BATCHMODE        = NO
 
 LATEX_HIDE_INDICES     = NO
 
-# If the LATEX_SOURCE_CODE tag is set to YES then doxygen will include source
-# code with syntax highlighting in the LaTeX output.
-#
-# Note that which sources are shown also depends on other settings such as
-# SOURCE_BROWSER.
-# The default value is: NO.
-# This tag requires that the tag GENERATE_LATEX is set to YES.
-
-LATEX_SOURCE_CODE      = NO
-
 # The LATEX_BIB_STYLE tag can be used to specify the style to use for the
 # bibliography, e.g. plainnat, or ieeetr. See
 # https://en.wikipedia.org/wiki/BibTeX and \cite for more info.
@@ -1994,16 +1927,6 @@ RTF_STYLESHEET_FILE    =
 
 RTF_EXTENSIONS_FILE    =
 
-# If the RTF_SOURCE_CODE tag is set to YES then doxygen will include source code
-# with syntax highlighting in the RTF output.
-#
-# Note that which sources are shown also depends on other settings such as
-# SOURCE_BROWSER.
-# The default value is: NO.
-# This tag requires that the tag GENERATE_RTF is set to YES.
-
-RTF_SOURCE_CODE        = NO
-
 #---------------------------------------------------------------------------
 # Configuration options related to the man page output
 #---------------------------------------------------------------------------