Fix default value display in help messages (#110)

To display the default value as set by the developer, ignoring the later assignments (from env vars, user input, ...)

Fixes #98

* Handle multi line option and argument description in the generated …

…help message #96

* Add support for float64 options and args #90
* Add Ptr variants to option/arguments where you can pass a pointers to existing variables #89

Added go.mod file, detect duplicate options/args

Fix parsing of long option values containing = sign (#75)

Rework help message formatting (#53)

Fixes an infininte loop in options matching (issue #55, fix in #56)

Fixes a bug in handling of multiValues values with a default value (#54)

First (tagged) release