initial commit
added a license (Apache v2)
first working version of the AnnDocuGen tool
added a simple build script
added field initializer reading and more examples
moved field initializer reading from custom ANTLR parser to Compiler Tree API

This sounds like it ties the implementation to the Sun Java Compiler,
but this tie was already in place with the previous implementation. In fact,
this implementation only relies on public APIs, even if they are
vendor-specific, while the old one relied on a private implementation detail
of a vendor-specific class.
handle Optional types properly

Proper handling of Optionals means:

1. Deciding if something is Optional is not based on comparing strings
   but actual types.
2. If a field is Optional and has no initializer, it is implied to be
   initialized to Optional.absent