Adding .backup extensions to .gitignore file for new projects.
Adding .backup extensions to .gitignore file for new projects.

RobertPeng/SpriteBuilder,DNESS/SpriteBuilder,apportable/SpriteBuilder,quicklyslow/SpriteBuilder,spritebuilder/SpriteBuilder,eric-seekas/SpriteBuilder,diogocarneiro/SpriteBuilder,DNESS/SpriteBuilder,olegnaumenko/SpriteBuilder,rraallvv/SpriteBuilder,spritebuilder/SpriteBuilder,oxeron/SpriteBuilder,spritebuilder/SpriteBuilder,rraallvv/SpriteBuilder,olegnaumenko/SpriteBuilder,rraallvv/SpriteBuilder,diwip/SpriteBuilder,rraallvv/SpriteBuilder,olegnaumenko/SpriteBuilder,olegnaumenko/SpriteBuilder,RobertPeng/SpriteBuilder,DNESS/SpriteBuilder,quicklyslow/SpriteBuilder,oxeron/CocosBuilder,quicklyslow/SpriteBuilder,rraallvv/SpriteBuilder,olegnaumenko/SpriteBuilder,oxeron/SpriteBuilder,ZeusbaseGameWorkshop/SpriteBuilder,diogocarneiro/SpriteBuilder,ZeusbaseGameWorkshop/SpriteBuilder,DNESS/SpriteBuilder,spritebuilder/SpriteBuilder,RobertPeng/SpriteBuilder,spritebuilder/SpriteBuilder,apportable/SpriteBuilder,RobertPeng/SpriteBuilder,DNESS/SpriteBuilder,oxeron/SpriteBuilder,diogocarneiro/SpriteBuilder,ZeusbaseGameWorkshop/SpriteBuilder,diwip/SpriteBuilder,diwip/SpriteBuilder,RobertPeng/SpriteBuilder,oxeron/SpriteBuilder,eric-seekas/SpriteBuilder,ZeusbaseGameWorkshop/SpriteBuilder,oxeron/CocosBuilder,apportable/SpriteBuilder,quicklyslow/SpriteBuilder,oxeron/CocosBuilder,oxeron/CocosBuilder,diogocarneiro/SpriteBuilder,diwip/SpriteBuilder,apportable/SpriteBuilder,spritebuilder/SpriteBuilder,oxeron/SpriteBuilder,oxeron/CocosBuilder,RobertPeng/SpriteBuilder,ZeusbaseGameWorkshop/SpriteBuilder,oxeron/CocosBuilder,DNESS/SpriteBuilder,quicklyslow/SpriteBuilder,eric-seekas/SpriteBuilder,apportable/SpriteBuilder,eric-seekas/SpriteBuilder,diogocarneiro/SpriteBuilder,eric-seekas/SpriteBuilder,diwip/SpriteBuilder,apportable/SpriteBuilder,eric-seekas/SpriteBuilder,oxeron/SpriteBuilder,diwip/SpriteBuilder,olegnaumenko/SpriteBuilder,ZeusbaseGameWorkshop/SpriteBuilder,diogocarneiro/SpriteBuilder