bit_array: added the possibility to create an empty array
bit_array: added the possibility to create an empty array

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