Added support for javascript byte code

A tool named "jsbcc" introduced to compile javascript files to byte code files
Byte code file uses ".bc" suffix. i.e. "test.js" will be compiled to "test.js.bc". 
When running, "test.js.bc" will be checked first, if not found, "test.js" will be used

Tested on iOS and Android, but no test cases included, for different repos.