WIP.
Do not create a message when:

When an existing item is updated within 6 hours after the initial insert
by the SAME user.
Merge remote-tracking branch 'origin/develop' into feature/CFD-193-Activity_stream_insert_update_messages
WIP for node_access_acquire_grants(), but in the end we will handle it on og.
Comments messages fixed.
Changed message creation and updating conditions.
Made general functions for insert_node and for update_node.
Code moved to pluggable_node_access.
Update.
Tests updated.
Comments. Tests are updated.
Use forked version of OG.
Use the right branch.
Start adding logic to components.
Merge branch 'develop' into 196
Added page Discussion edit.
Panels dependency.
Don't show selection of node types. Show discussion fields.
WIP: Set default values from the node that is editing.
Default values from the node that is editing. Send the right group id