docs: Add another way to view the Synnefo UI

Add instructions on how to connect to the Synnefo UI using a SOCKS
proxy.
deploy: Remove obsolete UI_MEDIA_URL setting

Deploy used to set UI_MEDIA_URL to point to the IP of the host
instead of its FQDN, to work around issues with the Java-based VNC
client and self-signed certificates. Synnefo v0.16 has obsoleted
the Java VNC console, so we may safely remove this setting.
admin: Fix typos in admin tests
admin: Fix typo in deleted entries tooltip

Remove the "None." string that appeared on every category (besides
projects) due to a bad template tag. Also, add the tooltip in a
separate html file for easier editing.

Fixes apyrgio/synnefo#288