Faster partition

Alex, the changes here make partition faster--the mileage will depend on your dataset. You can try out my version of the code first before merging by using "git clone git@github.com:marghoob/CNVnator.git" at a location which is in a different directory than your copy of your cnvnator repository. Then do "git checkout faster-partition" and then make. Try out the built cnvnator and see if it is faster and whether the output is the same. On my machine, the output was identical as before, which is what it should be.