Mailto link on thank you page
Use elasticache-specific lib
Add a prefix to these caches
Test environments need this lib
Tweaks for form

I ensured to add the text at the bottom, seeing as how it seems very
important, added the pay by check link Jeremy talked about (sorry I
paid very little attention to design of it) and other small things.
Merge pull request #185 from cmc333333/email-link

Mailto link on thank you page
Merge pull request #186 from cmc333333/memcached-lib

Use elasticache-specific lib
Merge pull request #187 from msecret/ehnc-donation_form_tweaks

Tweaks for form