Fix #1392884 [Static buffer overflow in unrar InitCRC](https://bugs.launchpad.net/calibre/+bug/1392884)
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Track when GUI processes are detached
Fix a regression in 2.10 that causes Adding books from sub-folders, one book per folder to incorrectly add OPF files present in the sub-folders as an extra format. See #1392864 (Errors in book import in 2.10)
Update the version of libimobiledevice bundled with the windows calibre build to support iOS 8
Use the default user shell in the build VMs instead of bash
Fixed libimobiledevice _afc_file_write wrapper to loop until all bytes are written.

_afc_file_write is used by the idevice interface to copy files to the
idevice. This fix has been successfully tested by round tripping a 500
MB file from the PC to the device and back again, and checking that the
before and after files are identical.