Keep the modified state for each view in the undo-state

Based on TortoiseSVN revision 24208

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>
Add menu entry to apply the patchfile by starting TortoiseGitMerge

Based on TortoiseSVN revision 24211

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>