added tests for Principal<> statistics
added tests for Principal<> statistics

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