Multi-view edit I.
 * Ask what file to save even more (both) are changed
 * Removing empty line do not mark view changed
 * For testing purposes new texts are constants


git-svn-id: http://tortoisesvn.googlecode.com/svn/trunk/src/TortoiseMerge@24074 4cfb86a4-2c7a-11df-bd14-c1e331e6ceac