Fixes bug with user searching
Adds user followers & following
Adds checking of user follow relationship

Aka if the authenticated user is following a user.
Removes unnecessary method

The method is already defined in an included 
module.
Changes account from Account to User

This makes it a lot easier to get a handle on the
authorized user: Kippt::Client.new(…).account
Adds user clips, favorites & likes
Updates TODO
Ruby 1.8 fixes

I don't know if there is any sense anymore to
support 1.8, but with these changes it still 
works.