Add support for os specific feature detection

Similar to how we have ruby feature detection this ports the `windows?` method from core and adds a method for detecting windows file paths (a sort of follow up to #108), idea would be to replace the usage of `world.windows?` with this and refactor #108 
This is from #108, @scarcher2 indicated that windows file paths weren't used on cygwin as it's a "unix" like environment on windows. FWIW I believe:
* `cygwin` - Cygwin https://www.cygwin.com/
* `mswin` - Desktop Windows
* `mingw` - MinGW http://www.mingw.org/
* `bccwin` - Bordland C compiler
* `wince` - Windows CE
* `emx` - No idea.

It makes sense to me that probably `bccwin`, `wince`, and `emx` be added to the file_path? regexp.