Fix a bug in the display of node text for the exploration graph in Firefox
Add 'My Explorations' tab to navbar.
Further fine-tuning of the navbar.
Allowing tests to be run on individual subdirectories.
Minor doc tweak.
Remove dependence of the gallery controller on the exploration model. Create an exploration services file containing actions that involve explorations.
Add the current user as an attribute of each request handler. Simplify the logic for the gallery controller.
Add missing decorator.
Add missing decorator annotation.
Merge branch 'master' of https://code.google.com/p/oppia
Add tests for gallery and base controllers.
Remove unnecessary imports, including sympy (which we will include later once we actually use it).
Minor linting.
Introduce an IdModel class.
Move get() method for IdModel classes to the common superclass.
Merge branch 'master' of https://code.google.com/p/oppia

Conflicts:
	apps/base_model/models.py
	apps/classifier/models.py
	apps/image/models.py
	apps/parameter/models.py
	apps/types/models.py
	apps/widget/models.py