update bok choy db caches
Annotation Tools: Added Grouping Plug-In

- adding comments

 - spacing issues and indentation
Merge pull request #4504 from lduarte1991/lduarte-harvardx-pr11

Annotation Tools: Added Grouping Plug-In
update bok choy db caches
Merge branch 'mvo/update_bok_choy_db_caches' of https://github.com/edx/edx-platform into mvo/update_bok_choy_db_caches
Merge pull request #4636 from edx/mvo/update_bok_choy_db_caches

update bok choy db caches