MahtMenu module bundle

MathMenu is a bundle created in the course of the DRMF project at NIST. It includes the following Context Menu entries as separate modules:
 * A simple display of the TeX source of a MathML formula
 * A clipboard workaround for copying the TeX source of a MathML formula, based on the ZeroClipboard library
 * A simple redirect to Wolfram Alpha with the TeX source of a MathML formula

Please review and request any changes you see fit, we are happy to contribute.