Squashed 'moose-gui/' changes from 2ba6bd5..2a1f94f

2a1f94f modelRoot is cleanup for plotting if its comes from genesis or sbml, cleanup in networkx clean while import graphvizlayout
9d55f14 Function can be now on pool class also, and networkx need not to be checked for version for using graphviz_layout, import from network.drawing took care off.
35fb3ac If python-libsbml libs in not found, gui was failing to report which is fix here
34df1fb found a way to use networkX graphviz_layout directly using a importing lib, now no need to check networkx version
7b160c2 corrected indentation
e3e5d2e Merge commit 'f0fd0e53'
a89f6b3 BhallaLab/moose#204.

git-subtree-dir: moose-gui
git-subtree-split: 2a1f94f4be0d4643956232d2eed290b649f12a71