lowercase all the things

This project may need to be renamed from `actionHero` to `actionhero` (lowercase) to conform to NPM's rules.  This branch does just that.

Other things to change:

- [ ] links in public website
- [ ] the make of this github repository
- [ ] make a stub with the camel-case name which redirects
- [ ] all URL links in the wiki
- [ ] the name of the mailing list