Remove docs
Replace New Relic with Exceptiontrap

We really just need error notifications, with backtraces and longish
retention windows (since there may be some latency getting to them).
Exceptiontrap isn't as fully-featured as some of the alternatives, but
The rention policy and price are right.
Lock sprockets

See the referenced github issue
Show user's past requests on new response view
Add response to recent history view
Refactor SMS ingest

Major motiviations here:
* Change format to support multiple shortcodes in one message
* Store record of SMS messages as they come in and link to the orders
  they create
* Don't require providing a pcv_id; try to look up account by phone
  number unless one is given

The last change obviously requires storing phone numbers and associating
them with user accounts, which is done in this commit, along with a few
other incidental cleanup items discovered along the way.
Flesh out incoming SMS handling
Extract user CSV uploader; add support for phone numbers
Support adding / editing multiple phone numbers for a user

Obviously, the styling needs some work
Add user upload spec and fix a few buglets
Improved user upload messages
Friendly number-not-found message
Group orders in the request manager
Use new Rails enum for User role
Functioning new response page
Fix order history on new response page

Also use icon helper consistently
Remove "orders since" auto-refresh

That was a hack over an actual auto-update solution. Since we're moving
towards checking the requests ~ once per month, live streaming doesn't
seem terribly important though.

Some various other incidental cleanup also in this commit.
Have response tracker track response objects
Add response show page
Remove line-item comments