device-manager: Don't emit device-removed with a finalized instance

https://bugzilla.gnome.org/show_bug.cgi?id=712812
input-device: Use g_clear_pointer

https://bugzilla.gnome.org/show_bug.cgi?id=712812
input-device: Fix a GArray leak

https://bugzilla.gnome.org/show_bug.cgi?id=712812
device-manager-xi2: Fix device instances leaking on removal

Don't add an extra reference when adding to the devices hash table. We
already own the initial reference.

https://bugzilla.gnome.org/show_bug.cgi?id=712812
device-manager-evdev: Unref devices on removal

https://bugzilla.gnome.org/show_bug.cgi?id=712812
device-manager-evdev: Fix a segfault on device removal

Master devices have a NULL sysfs path so use g_strcmp0 to handle them
without crashing.

https://bugzilla.gnome.org/show_bug.cgi?id=712812
device-manager-evdev: Stop using deprecated libevdev API

Fixes compiler warnings with libevdev >= 0.4 and makes use of a new
function to set the clock id instead of doing the ioctl directly.

https://bugzilla.gnome.org/show_bug.cgi?id=712816