renamed merge() => operator+=() in individual functors to make them more compatible
renamed merge() => operator+=() in individual functors to make them more compatible

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