[TIMOB-13133] Ti API: Implement support for file, line, etc "macros"

Node.js has two useful "macros" of sorts: __dirname and __filename (see http://nodejs.org/api/globals.html). We should consider adding similar macros of our own: * __file * __line * __function It's worth noting that Node.js only supports __dirname and __filename because they can be inserted as module-scoped variables, but __line and __column require compile-time support. It's a lot easier for us to do compile-time support (a true macro) than it is for Node.js, but it's still worth discussing this point. Note: for production builds, we should not insert this information. Strings should be undefined/empty string and numbers should be NaN This should be implemented as a CLI hook that uses uglify to walk the AST tree and modify it