Possible performance optimizations for pregel
Performance improvements for Pregel. Now uses Array structures
Improved pregel algorithm. Does not store edgecount any more, improves runtime...
Merge branch 'pregel' of github.com:triAGENS/ArangoDB into pregel

Conflicts:
	js/server/modules/org/arangodb/pregel/worker.js
Merge branch 'pregelOnSpeed' into pregel

Conflicts:
	js/server/modules/org/arangodb/pregel/edge.js