This adds an Antlr grammar for parsing argument lists instead of using a
hand written parser. This allows to write much more complicated syntax
constructs and have all the code being auto-generated. It will also
produce a much more correct parser instead of having all those hacks in
the hand-written one.
This also adds (in addition to supporting the previous syntax) support
for function types along with support for them in HTML and JSON output
formats.
The ANTLR generated parser is included in source form so that it is not
necessary to have an ANTLR installation around if you are not going to
change the grammar. Also includes the necessary runtime code from Antlr.
