#35 xcscope: FSF Emacs >= 21.1 enhancements

[Anonymous]

The third mouse button is bind to a popup menu for
cscope. The previous invoked find command is marked in
the cscope menu. Shift mouse button 3 invokes the last
find command again. E.g. if you look for the symbol
main and afterwards you want to look for another
symbol, just press Shift and click the third button.

[Nobody/Anonymous]

xcscope.el.diff with v15.3