Scaffolding of NavPanel
Texts browsing in navpanel basically functioning
Revert commentary ordering in TOC
Merge versions script
Merge branch 'master' into navpanel
Merge branch 'r2' into navpanel

Conflicts:
	sefaria/system/cache.py
	sefaria/system/context_processors.py
Preview texts in Nav Panel
Merge branch 'r2' into navpanel
fix get_texts_summaries_for_category from returning category nodes
hack to fix errors when browsing to urls containing unicode characters
Add tax ID number to donate page
Fixes and improvements to preview texts in nav panel
Merge branch 'master' into r2