Fix declaration after use in XVimInsertEvaluator

Following from 223a8e7d9fb and edec6506114, helper methods were declared
before use, and this broke the build out of the box for me on Snow
Leopard.
Merge pull request #304 from ches/build-fixes

Fix declaration after use in XVimInsertEvaluator
Implement C_g
Merge pull request #309 from pebble8888/cursorpos

Implement C_g
Quick fix for issue #265
This may lead another problem though
Merge branch 'master' of github.com:JugglerShu/XVim