ForemanApi 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