Allow stash message to start with a dash

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Drop unused msysgit dialog of installer

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Optimize text for TortoiseGitPLink checkbox

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