Merge pull request #4 from ptgreen/master

Expand LALR grammar to include lambdas, paths in struct exprs. Refactor stmts.
Update rlex/rparse for upstream changes
Add more stuff to gitignore
typo fix in comments
raw string literals
nested block comments
handle shebangs properly
Say LALR(1), not general LALR.
Add support for atomic (0-arg, owned-string) nodes in parser-lalr.
Use atomic nodes where appropriate in parser-lalr.
Modernize rparse to track trunk libstd.
Make rparse a bit more aggressive about filtering json.
Add sexp-printing mode to rparse, make JSON optional, tweak doc to mention it.