[api, webui] remove change_role in API and add a relationships controller

This makes the API routes clearer and the webui code uglier, but it's a
step in the right direction of clearer controllers in API
[api] remove duplicated code (hope to get an A now :)
[api] remove one more usage of rexml

3 XML parsers ought to be enough for any app
[api] simplify code of webui/requests controller
[webui][api] Introduce comments for projects, package and requests in the API and display them in the UI
[webui] Comments now expand and collapse
[api] Testing and validation for comments
[api][webui] ran migrations and fixed routes for comments in request
[webui] removed package file count. Was a test and now unnecessary
[webui][api] implemented feedback received on PR about exception handling, AR calls and other tid-bits
[webui] refactored child comment reply links & display
[webui][api] refactoring to make the code more object oriented
[webui][api] working on POST calls (WIP)
[webui][api] Refactoring. GET and POST now working via JSON. Object oriented code now in place too.