Code formatting.
Cleanup of CommandArguments-related stuff and a bug fix
* fix CommandArguments.complete() not adding space after closing
unclosed quote
* add some TODOs
* change CommandArguments.index from package-private to private
and add a getter
* change CommandArguments.get() to return unmodifiable list
* add CommandArguments.getAll()
* remove CommandArguments.getLive()
Improve creation of CommandArguments of flags
* add CommandArguments.subArgs()
* add protected constructor and getPaddings() to CommandArguments so
that its methods and subclasses can perform operations similar to
subArgs()
* make DefaultFlagSyntax use subArgs for flag arguments. This preserves
paddings, but doesn't preserve arg overrides yet.
Implement flag completion.
Add helper methods for merging 2 completion results to CommandArguments
Add missing license headers