Wrap up the list of topics in the new-style page.
Reinstate the note about citing TWFY.

Removed the journalist-specific bit, as this should also apply to all
citations (eg academic).
Implement new Analytics plugins to provide richer engagement data.

[Riveted](http://riveted.parsnip.io/)
[Scroll Depth](http://scrolldepth.parsnip.io/)
Merge branch 'improve-engagement-tracking'
Escape dollars in replacement strings in email templates

Fixes #499, as suggested by Matthew Somerville

I've added a simple test for the utility function; ideally, however, there
should be a test that generating the email text (i.e. the caller of this
code) works correctly.  To do that I'd refactor send_template_email to
separate the generation of the email text from the sending, so that those
can be tested separately.  However, this is just a quick fix on a busy day
when I'm meant to be working on other things...
Update the rewrite rules in the nginx config

These rewrite rules were updated in httpd.conf but not the example
nginx.conf file.

The MP page redirect updates correspond to the change in:

   401796933c6adb2ec468c3df723579f6d8a455b9

... which was updated again in:

   f92768ebc3cf02b8a39f07ea51cd48d44619113f

The confirmation link update was from:

   bf4ee507b73999ece8d644e8da4d15617fb8fa18
Fix broken search for exact constituency name.

There was some bad logic whereby if a search matched a constituency name
exactly, nothing was returned from the constituency search. Fixes #392.
Merge branch '448-note-for-journalists'
Merge branch '499-fix-confirmation-code-emails'
Hide promotional banner

leaving code in there as we seem to need this reasonably often
Change CSS output to compressed
Disable line comments in CSS output
Move MP profile CSS into a partial to make maintenance easier
Convert existing topics to new rendering system.
Remove stray end-of-line spaces in httpd.conf
New Member class with single isDead() function
New PolicyPositions class to interact with members' policy positions.

Code mostly taken from existing MP profile page.
Introduce new single topic controller.
Add list of MP positions to topic page.

Also moves topic data from distinct files into the top of the topic
controller.
Migrate MP profile pages to use new PolicyPositions class.

Closes #475