Fix Repository Browser said commit not found in submodule

Fix regression of a86f4a8206203ac19ebfa49ef8f21e58532f511b.

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>
Signed-off-by: Sven Strickroth <email@cs-ware.de>
Fix includes

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Deduplicate "explore to" code

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Fix calls to OnCaretMove()

Based on TortoiseSVN revision #25710.

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Ensure drawing of whitespace indicators is always right of the margin

Based on TortoiseSVN revision #25712.

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