Extract out posssible exec path functionality from getExecPath to getPossibleExecPaths. Added detection for .bat aliases on windows.
v2.2.5. Improvement.

- v2.2.5 June 29, 2013
	- Split out possible exec path functionality from `getExecPath` to
`getPossibleExecPaths(execName?)`
	- Added support for `.bat` aliases on windows to `getPossibleExecPaths`
	- More efficient possible exec paths ordering when on windows