GVFS 1.17.0 Features Better Support for Android Devices

GVFS 1.17.0 enhances the demon by ensuring that monitors are not prematurely finalized, a crash when cancelling channel operations was fixed, read sizes were tweaked, channels belonging to the active mount are now closed, and an infrastructure for the backends to exit cleanly was added. Moreover, this development release of GVFS improves the MTP function by using Android extensions to support in place write and read of files, uses normal filenames in paths, children of cache entries are now removed too, previous cache entries are now cleared when refreshing a directory, and the SD Card icon uses standard name.