Patch Set 1: No score; No score

as agreed with Igor 
http://dev.eclipse.org/mhonarc/lists/egit-dev/msg00400.html 
this change replaces 
- http://egit.eclipse.org/r/#change,126 Change Icebfffdc: partially working tycho build configuration
- http://egit.eclipse.org/r/#change,127 Change Ic384b918: Merge commit 'origin'
- http://egit.eclipse.org/r/#change,129 Change Ia9f596ab: Merge commit 'origin'
- http://egit.eclipse.org/r/#change,130 Change I6198622b: New org.sonatype.tycho groupId..
- http://egit.eclipse.org/r/#change,128 Change I1cd9ec0f: flipped jgit.core to manifest-first

Igor: add whatever is pending from Robin's comments in http://egit.eclipse.org/r/#change,128
and review the commit message again.

- lcp says this patch has 234 lines hence we are below CQ threshold
- tested build on Windows XP successfully