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 specified, 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
 included 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
* fix development dependencies