Edited storage and storing code required for branching

Added a branchhead store (BytesStore), a userhead store (BytesStore). Changed tests and inits of Backends.

Learned the code of routing middleware. It seems that there is no proper routing now and seems that there is nothing to change there for me. TODO.

MoinMoin: GoogleSoc2012/BranchMergeSync/2012-06-15 (last edited 2012-06-16 10:15:04 by BorisBobrov)