[IMP] stock: allow float precision for quantity qty multiple

e.g. if orders with packages of 1/2 quantity
[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