added paper trail + fixed agreement negotiation permission problem
added paper trail + fixed agreement negotiation posting_rule permission problem
basic diff table is working with rules specification
basic diff table is working with rules specification + validation that one can't accept if already made changes to the agreement. to discuss with Ishay on the design
agr track changes - props that changed are now marked with the changed css class
agreement track changes - everything is working missing notification
#270 - agreement negotiation is ready for styling (read more for details)

last few changes should be more evident
need to style the notification
need to ensure wording in YML is good enough
#270 - Agreement Rejected Notification is ready for styling
Merge branch '#270-track-agr-changes'

Conflicts:
	app/assets/stylesheets/all/bootstrap_and_overrides.css.scss
#270 - added changed css class