Use typhoeus by default
Introduce request classes

Basically they're wrappers around the related library, and the
idea is to make easy the switch and customization of new libraries
Make use of requesters classes

- tweaks in api, to make use of current requester class
- adds related methods to configuration class, to make easy
  the switch between requesters
- fix command line
Adds documentation
Removes typhoeus config
Read key value from Embedly::Configuration

So that the API key doesn't have to be entered on every time
Embedly::API is instantiated.
Merge branch 'key-in-config' of https://github.com/coffeebite/embedly-ruby into coffeebite-key-in-config

Conflicts:
	lib/embedly/api.rb
Merge branch 'adapters' of https://github.com/felipeelias/embedly-ruby into felipeelias-adapters

Conflicts:
	lib/embedly/api.rb
	lib/embedly/command_line.rb
Remove functional tests against api
Remove old typhoeus config check
Merge branch 'coffeebite-key-in-config'
Doc updates
Version bump to 1.8.0
Regenerate gemspec for version 1.8.0