Certificates: Add regeneration command

* Adds regenerate_user command, which lets you run certificates for one
  particular user in one particular class, regardless of whether they
  have a pre-existing certificate.
Remove adding prefix to custom parameters.
Fix a malformed custom_parameter bug.
Fix custom parameter.
Revert "Fix a malformed custom_parameter bug."

This reverts commit 75bdc1eebfd444bf00102b486a881f5776bbc407.
Fix comments.
Merge pull request #1291 from edx/anton/fix-lti-custom-parameters

LTI: Fix bugs related to custom parameters.
Release email script: use --no-pager
Merge pull request #1428 from edx/db/release-email-no-pager

Release email script: use --no-pager
adding STATIC_ROOT
adding STATIC_ROOT to cms
password reset pages use Django templates, not Mako
Add neglected entries
Merge pull request #1432 from edx/dhm/changelist_update

Add neglected entries
Use known translation if exists to get groupname
Merge pull request #1431 from edx/db/password-reset-fix-static

password reset pages use Django templates, not Mako
Add synchronization logic to fill, check, and select
Test that instructors can access courses
Refactor wait_for methods in ui_helpers for acceptance tests.
Remove as_old_location methods
They were incorrect if there were periods in the org or name.