1) Added API to get centers / sectors / zones which user has access to for a particular role.
2) Changed is? API to return always true for a super admin.
Added scope for "by_role" which will b used for fetching access privilleges based on a role name and this will be used for getting centers for a particular role of a user.
1) Added condition to show / hide the menus based on role.
2) Filtered centers drop down based on the role.
Merge branch 'amit' of https://github.com/bishups/pcc-main into amit