Ship all overlay icon sets TortoiseSVN ships

(fixes issue #1956)

Signed-off-by: Sven Strickroth <email@cs-ware.de>
TortoiseGitIDiff: Fix could not load icon file

Fix regression of b6a32b2c71dd4ed6f0a91b72f3416ed0064a1927

Based on TortoiseSVN revision 24898

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