Add more extended permissions control for Roles in group based modules

[rednaxal]

Roles in groups based modules need more granular control to who can do what.
Each role in a backend should have an on/off switch for
group base entry itself:
Entry edit
Entry change cover
Entry manage roles
Entry manage fans
Entry invite

for each content module which can post into a group's context
Post
Edit any entry
Delete any entry

In addition to the above add an ability for an organization to post into its own context.