follow recent rust changes
Merge pull request #1 from Fiedzia/master

follow recent rust changes
rust: Box, String
allow(non_snake_case_functions)
Use libsyntax to generate Rust code
Add a quick README
Mergeing from kevinmehall/rust-peg.

Conflicts:
	bootstrap.sh
	examples/test_grammar.rs
	src/peg/codegen.rs
	src/peg/grammar.rs
	src/peg/grammar.rustpeg
	src/peg/main.rs
	src/peg/peg.rs
	test.sh
fix examples/test_grammar.rs