Basic operators for Fixnum and Float
Unless loop implementation
Improved handling of file requiring
issue #82
Fixed file requiring
issue #83
Regexp class
Big code refactor
 - Context is not a singleton
 - Exposer class to bring C written modules to Rvby
 - Separated JIT copiler code
Split to modules (librvby, librvbystd, rvbyc)
Early support for .so loading