FWB-40684-webstore-module-backend

Allow fw_sig params to be sent in headers

Gives us an alternative to the existing parameter-based implementation
Also update source control management for Webs in 2014
Also should update that readme, it's over 4 years old at this point...

Also someone needs to give me (will-webs, william@webs.com on rubygems.org) push rights to this gem.
Sorry, I should have been more clear. You're doing
```ruby
request.headers[x]
```
In this code, `x` is a string. In your addition to the README, `x` is a symbol.