issue_23: display git hash of current version in the bottom toolbar. Or hide it if its not a git repo

Conflicts:
	crits/core/templates/base.html
Made display of current git hash more efficiently done.
Slight style changes. Moved git_repo_url to be a user inputted field in the control panel view
Removed seperate git hash section from bottom toolbar
Removed ISPROD. Changed link to take you to current commit. Slight style change.

Conflicts:
	crits/core/static/css/core.css
Merge remote-tracking branch 'crits/master' into release_version_pub

Conflicts:
	crits/config/forms.py
	crits/core/templates/base.html
Fixed error caused by overlooked merge conflict
Merge branch 'master' into pr/215

Conflicts:
	crits/core/static/css/core.css
Merge branch 'master' into distributed_services