Implement FilterFactory with errors for karsten to fix
Merge branch 'FilterFlamingo' of https://github.com/V02460/CTT
back for kai to fix
Merge branch 'master'
Add fragment shader for BlurFilter
Make tests work again
Finish GreyscaleFilter for it to be instantiatable
Merge branch 'master' into jonas
Adds some Tests, fixes some mistakes these tests find.