Win32: Port Directory Monitoring to New GLocalFileMonitor

Win32: Port Directory Monitoring to New GLocalFileMonitor

This WIP patch moves the Windows Directory Monitoring code to the new
GLocalFileMonitor mechanism, and adds file monitoring in the process.

Progress from previous patch:
-File renames are now properly supported, but G_FILE_MONITOR_EVENT_MOVED_IN
 and G_FILE_MONITOR_EVENT_MOVED_OUT needs to be investigated, as
 ReadDirectoryChangesW() seems to send FILE_ACTION_REMOVED when a file is
 moved out of a directory.
-Events are handled for both the long and short (8.3) variants of the
 filenames, and files monitored will report changes when it is changed
 via its short or long filenames.

Things to be done:
-Perhaps find out about attribute changes in files in a monitored
 directory; if a file is monitored, attribute changes are correctly
 handled.
-Investigate on G_FILE_MONITOR_EVENT_MOVED_OUT,
 G_FILE_MONITOR_EVENT_MOVED_IN, G_FILE_MONITOR_EVENT_PRE_UNMOUNT,
 G_FILE_MONITOR_EVENT_UNMOUNTED.
-Investigate on the "boredom" algoritm, and see how we can do it on
 Windows.

https://bugzilla.gnome.org/show_bug.cgi?id=730116