Upgrade newrelic agent to the latest version
Move mitxmako initialization to a startup module, called by lms.startup and cms.startup for both management commands and when run via wsgi

[DEVPAIN-7]
Rewriting of links for Course Updates and Course Handouts.

STUD-669.
Slightly change email registration template
    Added some text to guide the student to register with a particular email address.
    This is the one that was entered into the enrollment/invitation form by the instructor.
    Modified the template and associated test.
Merge pull request #827 from edx/christina/course-info-links3

Rewriting of links for Course Updates and Course Handouts.
Instrumented course email for DataDog
Reset 'correctness' visual indicator of a problem on new input

Affects:
Choicegroups, option inputs, textline, and formula equation inputs
Merge pull request #834 from edx/dcadams/fix_email_registration_template

Small change to email registration template
Kill processes after running rake
Merge pull request #831 from edx/will/statsd-bulk-email

Instrument course email for DataDog
Merge pull request #838 from edx/fix/kill-rake-processes

Kill processes after running rake
Merge pull request #794 from cpennington/upgrade-newrelic

Upgrade newrelic agent to the latest version
Merge pull request #811 from cpennington/initialize-mitxmako-at-startup

Move mitxmako initialization to a startup module
using mocks to make test_err_handling.py faster
remove vestigal references to fake_smtp_server
restructure calc
specify preview import statements to reflect new package structure
change calcfunctions -> functions
bump version number on calc
Merge pull request #843 from edx/adam/calc-refactor

Adam/calc refactor