KatelloApi improved generator

* ability to determine the right request url based on params provided

  Given this paths:
    1. +/comments+
    2. +/users/:user_id/comments+
    3. +/users/:user_id/posts/:post_id/comments+

  If +:user_id+ and +:post_id+ is pecified, the third path is
  used. If only +:user_id+ is specified, the second one is used.
  The selection defaults to the path with the least number of
  incuded params in alphanumeric order.

* extract most of the generated code outside of template
* reuse documentation.json got from apipie.json when determining the
  request path
* make sure the params from path are included in the documentation
Bump katello_api version