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
Reuse course creator user in bok-choy tests and have them not be global staff
Deprecated unit tests from rake to paver
updating diff-cover, adding --compare-branch feature to paver task
Set verbosity on paver test tasks
Remove unused `verbose` property
Reverting commit @3bfb633 and updating openseadragon.js for latest build
Merge pull request #3944 from edx/zoldak/bok-choy-user-not-staff

Bok choy tests should not all run as global staff
Merge pull request #3945 from edx/clytwynec/rake2paver-tests

Deprecated unit tests from rake to paver
Merge pull request #4019 from lduarte1991/lduarte-harvardx-pr2

Annotation Tools Reverting commit @3bfb633 and updating openseadragon.js for latest build
locking version of requests-oauthlib to 0.4.0

requests version 1.2.3 does not appear to be compatible with the
new version of requests-oauthlib.

requests-oathlib tries to import to_native_string in util.py:

```
File
"/root/.virtualenvs/edx-platform/local/lib/python2.7/site-packages/requests_oauthlib/oauth1_auth.py",
line 10, in <module>
    from requests.utils import to_native_string
ImportError: cannot import name to_native_string
```
Added logging for sender email address on BotoServerError.
LMS-2734
Merge pull request #3978 from edx/waheed/lms2734-added-logging-for-email

Added logging for sender email address on BotoServerError.