Encrypt the session id before writing to tracking logs.
Also use md5 for constructing key for hmac.
Fixes BLD-1104
Add additional tests for tracking of sessions.
Merge pull request #3962 from edx/dcs/BLD-1104

Fixes BLD-1104
Product stack documentation

DOC-448
fix nfsd in devstack
Move .pep8 content to setup.cfg
Merge pull request #3954 from edx/brian/fix_session_id

Encrypt the session id before writing to tracking logs.
making system status notifications flexible based on content
Merge pull request #4002 from edx/db/move-pep8-to-setup-cfg

Move .pep8 content to setup.cfg
Fix performance regression
Remove course_from_id
don't fetch whole course when the root will do
don't fetch even the root if the id will do
check for definition.data == null
OpaqueKey copy and deepcopy are identity ops
because keys are immutable
pymongo son optimizations
Update to tagged version of pymongo
Use commit hash v tag for pymongo
Update hash to latest version.
Fix variable name.
Revert back to mongo-python-driver based on the 2.4.1 tag.
Add fallback for org based roles