Can disable TortoiseMerge TaskDialog on Win 7
This allows to test the traditional workflow on Win 7 without running in a real Win XP

git-svn-id: http://tortoisesvn.googlecode.com/svn/trunk/src/TortoiseMerge@24394 4cfb86a4-2c7a-11df-bd14-c1e331e6ceac