Merge develop into master for v0.5.1 release#183

Merged

pkra merged 5 commits intomasterfrom

Feb 22, 2016

Commits on Feb 19, 2016

Update README.md
Pomax
committed

Commits on Feb 21, 2016

Make test for node hierarchy more robust. Resolves issues #172 and #179.
dpvc
committed

Commits on Feb 22, 2016