The parser now gets a stream of tokens, rather than needing to worry about
loading files itself.
This also reworks the lexer's idea of what constitutes a Token -- it's now a
pair (Meta, TokenType), so it's always easy to pull out/rewrite the metadata --
and adds proper support for lexing preprocessor directives, rather than just
treating them as reserved words.
The compiler itself is under the GPLv2+; the support code that gets built into
user programs is under the LGPLv2+. This matches the existing practice for the
KRoC project.
(As with Occade, I've used the new GPLv3-style license header in the source
files, though, since that avoids having to update the FSF's postal address.)
