LoginForm: bugfix, reference proper variable
Browser plugin: implement own extended class, remove patches

Supply our own implementation of the browser plugin, based on the
SabreDAV-1.8.6 code with our patches applied. This obsoletes the patch
dir, and the patch process during the install.
composer.json: no longer tied to 1.8.6; allow higher

After removing the browser plugin patches, we are no longer tied to
SabreDAV-1.8.6, but can use all versions from the 1.8 branch. Change the
Composer config to reflect that.
Move all of SambaDAV to a PSR-0 compliant directory structure

This enables autoloading of all classes using the Composer autoloader.
It also makes this application conform closer to modern PHP best
practices.
Config: introduce static class to hold global config settings

Previously, the config was passed around in global variables.
Merge pull request #2 from aklomp/cleanups

Some cleanups done in my spare time