Fixes #68, fixes #80, fixes #81, fixes #7, fixes #65

Fixed the issues concerning SetBrightnessBricks / byValue,
SetGhostBricks / byValue

and
improved the escaping html entities method
merge
Merge branch 'spritekit' of https://github.com/Catrobat/Catty into spritekit

Conflicts:
	src/Catty.xcodeproj/project.pbxproj
	src/Catty/NSString+CatrobatNSStringExtensions.m
fixes #9 and fixed some warnings

ClearGraphicEffectBrick implentation and parsed the date in the parser