added convolution convenience functions
added convolution convenience functions

dagophil/vigra,hmeine/vigra,funkey/vigra,stuarteberg/vigra,ThomasWalter/vigra,DaveRichmond-/vigra,timoMa/vigra,dagophil/vigra,hmeine/vigra,mmuellner/vigra,hmeine/vigra,DaveRichmond-/vigra,stuarteberg/vigra,stuarteberg/vigra,cha007/vigra,timoMa/vigra,xiwei-zhang/vigra,timoMa/vigra,mmuellner/vigra,kod3r/vigra,kod3r/vigra,kod3r/vigra,xiwei-zhang/vigra,stuarteberg/vigra,capturePointer/vigra,cbecker/vigra,cha007/vigra,kod3r/vigra,ThomasWalter/vigra,DaveRichmond-/vigra,ThomasWalter/vigra,capturePointer/vigra,mmuellner/vigra,martinsch/vigra,ThomasWalter/vigra,xiwei-zhang/vigra,dstoe/vigra,dagophil/vigra,cbecker/vigra,cbecker/vigra,xiwei-zhang/vigra,funkey/vigra,xiwei-zhang/vigra,psteinb/vigra,DaveRichmond-/vigra,xiwei-zhang/vigra,capturePointer/vigra,timoMa/vigra,psteinb/vigra,cbecker/vigra,dstoe/vigra,kod3r/vigra,cha007/vigra,cbecker/vigra,timoMa/vigra,martinsch/vigra,cha007/vigra,dstoe/vigra,psteinb/vigra,hmeine/vigra,martinsch/vigra,cha007/vigra,psteinb/vigra,dstoe/vigra,cbecker/vigra,cha007/vigra,hmeine/vigra,funkey/vigra,psteinb/vigra,dagophil/vigra,DaveRichmond-/vigra,capturePointer/vigra,ThomasWalter/vigra,mmuellner/vigra,martinsch/vigra,DaveRichmond-/vigra,mmuellner/vigra,mmuellner/vigra,cha007/vigra,martinsch/vigra,dstoe/vigra,psteinb/vigra,funkey/vigra,timoMa/vigra,ThomasWalter/vigra,ThomasWalter/vigra,DaveRichmond-/vigra,kod3r/vigra,dagophil/vigra,dstoe/vigra,funkey/vigra,stuarteberg/vigra,funkey/vigra,capturePointer/vigra,psteinb/vigra,xiwei-zhang/vigra,funkey/vigra,dagophil/vigra,dstoe/vigra,dagophil/vigra,stuarteberg/vigra,capturePointer/vigra,hmeine/vigra,hmeine/vigra,kod3r/vigra,stuarteberg/vigra,martinsch/vigra,capturePointer/vigra,mmuellner/vigra,timoMa/vigra