Fix context menus

This pull request fixes:

1. Context menus not working when debugging or not debugging.
2. Snippet compiler exe crashing on 64 bit Windows.

The context menu issue was reported on the SharpDevelop forums.

http://community.sharpdevelop.net/forums/t/16780.aspx

Since my original Snippet Compiler sample for SharpDevelop 3 is not going to be updated or maintained I thought it would be better to fix the problem in your version of the code.