[horde] Test Page, CSS Caching & ActiveSync improvements

[Ralf Lang]

Hello,

over the last few days we had a series of improvements.

Torben and Dmitry worked on ActiveSync issues - see last night's release of
mnemo and some other components.

I fixed some bugs with CSS caching and while I was at it, made some
improvements to the admin tools.

- The admin/cache.php page now has a button to wipe the css cache and a
display of items in css cache (this feature didn't make it to last night's
release and is available in git - I needed some last minute touchups after
testing)
- The "test.php" page has gotten a complete overhaul. Test pages can now
have multiple sections and the "horde" test page in particular now has
multiple new features besides some reorganization.

 Horde [Horde]: 6.0.0-beta12 (run tests
<http://localhost/horde/test.php?app=horde> | PHP Configuration
<http://localhost/horde/test.php?app=horde&type=php> | PHP Info
<http://localhost/horde/test.php?app=horde&type=phpinfo> | PHP Extensions
<http://localhost/horde/test.php?app=horde&type=extensions> | Protocols
<http://localhost/horde/test.php?app=horde&type=protocols> | Routes
<http://localhost/horde/test.php?app=horde&type=routes> | Static Assets
<http://localhost/horde/test.php?app=horde&type=static>)

I also reacted to some feedback on the colour scheme as it sometimes
conveyed the wrong impressions with too much red in the wrong places.

The "Static Assets" test page provides several insights and tests about the
"static" dir, also used by the CSS Cache system.

The "Protocols" test will check some common pitfalls with ActiveSync, DAV,
json-rpc and SOAP and has some interactive tests which will require user
credentials. We don't automatically use your user session for obvious
reasons.

The test.php is hardened to work in many scenarios which have your horde
admin UI broken. Remember, this is an unauthenticated page revealing
critical system insights - always DO disable the admin page when you are
done testing or configure your webserver to expose the page only to
specific IPs.

Finally, the user powercycle on github provided a PR to unbundle sabberworm
from the horde/css-parser library. This is something I intended to do
myself but didn't get around to. I am very glad he did. Unbundle
sabberworm/php-css-parser by powercycle · Pull Request #6 · horde/Css_Parser
<https://github.com/horde/Css_Parser/pull/6#pullrequestreview-4035299762> I
will "release" this last change after some more thorough testing - the last
weeks were a bit hard on everybody's patience.

Thank you all for contributing tests, feedback, bug reports or fixes!

Ralf