Merge pull request #1 from ukoethe/master

from master to my fork
first version of merge graph with unit test
changed implementation of hasEdge from map based to ufd based (on the way to remove any map)
changed implementation of hasEdge from map based to ufd based (on the way to remove any map)
made partiotions rep. iterable
removed dynamicEdgeMap from ufd
 implementing strong unit test for merge graph w.i.p.
imporved unit test with very strong 3x3 grid test
fixed bug in merge_graph unit test
extended unit test
extended merge_graph unit test
strong grid unit test almost finisehd
fixed bug in partions iterator if no element is in the set
first base impl of accumulator chain map
improved impl. of min indexed pq and started an inital (so far very very very small) unittest
proof of concept of accumulatorChainMap is done (with basic unit test)
callbacks finished
refactoring of merge graph
multiarray map (and python wrapper)
added cgp includes