Performance tweak: most shout methods can return references now and the driver

Performance tweak: most shout methods can return references now and the driver
backend caches much more data.
More UI tweaks, experimenting with dialplan UI options.
**** NOTE ****
This version now relies on an edited HORDE_BASE./lib/Horde/VarRenderer/html.php
to render the new form type 'priority'. This is a test, we'll see how it works
out

git-svn-id: https://svn.alkaloid.net/gpl/shout/trunk@67 06cd67b6-e706-0410-b29e-9de616bca6e9