Add override details to validate's docstring
We require lazy. Docs were broken without it.
Merge pull request #272 from edx/ned/fix-docs

We require lazy. Docs were broken without it.
Fix the link to workbench
copy over b63bb0 import fixes to xblock/reference/plugins.py
version 1 of the user service, supporting get_current_user
Merge pull request #273 from edx/jbau/user-service

version 1 of the user service, supporting get_current_user
Merge pull request #270 from edx/andya/improve-validate-docstring

Add override details to validate's docstring
XBlock and Asides common behaviors
Asides special behaviors