[ADD] added rating, rating_project and rating_project_issue module

[IMP] Added option to install rating module under Project

[IMP] added template to display when customer rates the task/issue

[IMP] Improved template and code

[IMP] : rating , rating_project and rating_project_issue as per new api

[IMP]: rating template

[FIX] : test case failed

[IMP] : code

[ADD] : tooltip on rating kanban view and filter for unhappy

[ADD] : defualt groupby users in rating statastics

[IMP] Added conditions to show smileys on project kanban

[IMP] :message is post only when res_model have a 'message_post' method

[IMP]: method send_request

[IMP] : code and proper directory structure

[IMP] : code as per pep8
[REM] : unused csv

[REN] : rename state field to rating on rating obj
[FIX] : on project kanban smiley not display properly

[FIX] : smiley not display with 0 value , because it will consider False in rawvalue