lexer extracted from Lua 5.2
fixing bugs in string table translation.
refactored string formats.
parser from lua extracted.
significantly cleaner parser file.
parser tracks local variables (need so that terra can access lexical scope)
renaming symbols to get out of the way of actual lua API
adding dependency on luajit
added mechanism to patch output while keeping statements on the same line as original code.
fixed parsing bugs.
can now inject values into parsed code.
added a terra_State object and initial functions.
asts are built for ifstmts and functions.
ast rules for most statements.
better assertions;
most expressions can be parsed now.
more complete ast constructor.
support for [local] terra stmt declarations.
parsing types
added var a = b statements.
terra constructors now capture the local environment.
fixed off by 1 error when patch occurs at EOF.