Add PPA source files to configuration, along with new XFCE 4.10 PPA
Add new configuration files for XFCE 4.10

XFCE 4.10 required some new configuration changes to be merged in. thunar.xml
now contains code to hide 'Network' from the Thunar side panel.
Change keyboard shortcuts to use exo-open for generic applications
Remove .gtk-bookmarks code and add to allow list for configuration backup

Thunar now displays network shares under 'Devices', so the 'Places' shortcuts
(in .gtk-bookmarks) are no longer needed. In turn, .gtk-bookmarks can be
saved as a configuration file to allow users to save side-bar shortcuts
Add gvfs network.mount disabler

Prevent long startup times in Thunar on certain networks by disabling network
automount in GVFS. Was previously implemented, now has been copied to
configuration folder
Merge package changes to configuration files
Change unlocked attribute to include sudo group and root

The sudo group is one of the groups 'administrator' is put into, and root
has no groups but its own. So these additions allow administrator and root
to modify the configuration of the system, along with tech users from the
domain.
Add lightdm configuration files
Update panel to fix action buttons widget
Add checks for domain user in pre-session
Add checks for domain user second part
Revert "Change keyboard shortcuts to use exo-open for generic applications"

This reverts commit b5aa2701306c0cbe7b69a60adad238ca42f7ec7d. exo-open only
works for web browser, mail reader, terminal emulator and file manager
Fix session menu, fixes #16
Fix problem with preferred application dialog, closes #14
Merge branch 'xfce-4.10'