Merge pull request #11 from tbranyen/gamepad

Gamepad
Ensure JSMESS is globally exported.

This patch exports the internal module to the global scope.  At the
moment it isn't which is breaking for external scripts doing:

    var JSMESS = window.JSMESS || {};
Added a getRequest method for XHR operations.
Converted get_request to simplified CJS.
Updated and cleaned up the example JSMESS HTML.
Merge pull request #16 from tbranyen/housekeeping

Minor housekeeping with the HTML.
Merge pull request #15 from tbranyen/get-request

Better XHR requests.
Merge pull request #12 from tbranyen/fix-integration

Ensure JSMESS is globally exported.
Moved gamepad to a features subfolder.
Corrected paths for gamepad tests.
Updated modules to identify their location.
Added module to define signature.