admin: Update admin logout

In order to logout properly without using the astakos' urls, we will use
astakosclient.

More specifically, we will use the 'ui_url' property of astakosclient
that holds the url for the UI of Astakos and we will append to the end
of this url the '/logout' string. The user that requests to logout will
therefore get redirected there.

Fix apyrgio/synnefo#117
Merge branch 'feature-admin-logout' into feature-admin
admin: Show current place in navbar properly

Fix apyrgio/synnefo#122
admin: Update modal verification

Use action name instead of OK and remove verification message.
The only thing left to close the apyrgio/synnefo#127 issue is to move
the buttons to the left and right corners of the modal.
apyrgio: Update VM ID filter

Make the filter handle the server prefix, if given.

Fix apyrgio/synnefo#138
admin: Rename "Release suspension" to "Unsuspend"

Fix apyrgio/synnefo#146
Merge branch 'feature-admin-0.16-issues' into feature-admin
Add bootstrap sass files and style initial cleanup
Include cached and backup sass files to .gitignore
admin-ui: Add informative tooltip into home page
admin-ui: Move toggle-selected button

Fix apyrgio/synnefo#125
Merge branch 'feature-admin-ui-new' into feature-admin