Update Scintilla to version 3.5.1

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Adjusted and applied backgroundcolors.patch

Based on TortoiseSVN revision #25925.

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

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>
Merge branch 'scintilla-3.5.1'

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Fix typo in changelog

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