Drop TGit custom sounds and use system sounds instead

Inspired by TortoiseSVN revision #25681.

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Make context menu more like the one in notepad

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Use getters

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Update includes to not include directory modifiers

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Update scintilla style indicator code

This fixes a regression (incorrect styling in commit dlg message box) introduced in revision #174025195e72f250ebc9b8ac6fab3d3bf2630d12.

Based on TortoiseSVN revisions #20318, #21388, #21956 and #24725.

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Log Message / Progress Dialog context menu Select all also does copy

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