Add .gitignore to ignore those cache and manifest files

Signed-off-by: Antti-Ville <antti-ville.jokela@myy.haaga-helia.fi>
Merge branch 'master' of https://github.com/Fynze/ProjectCorePhase
Add .suo extension to the gitignore

Signed-off-by: Antti-Ville <antti-ville.jokela@myy.haaga-helia.fi>