Patch Set 1: No score; No score

Inspired by comments from Johannes Schindelin (see http://dev.eclipse.org/mhonarc/lists/egit-dev/msg00381.html) I reworked the merge algorithm. I changed especially the classes which contain the merge result.
Additionally I made small adjustments to the core algorithm when it comes to harmonizing conflicting edits.
Also some more tests have been added.