Web: refer to CRABID as Job ID on config page.

This is for consistency with the rest of the web interface.
Server: restrict passing of entire configuration.

Instead of passing the notification service constructor the
complete Crab server configuration, pass it only the notify
section and a pre-constructed CrabNotify object.  The CrabNotify
constructor still needs the complete configuration to prevent
the crabd server launch script from needing to know about
notification methods, but it need only pass the relevant
sections to each notification method class constructor.
JS: make invert optional with ANSI colors.

There is now a separate button which can be used to invert the
colors if necessary.