Initial commit of changes supporting cached booklist.
Additional work on caching/restoring booklist, cleanup.
Tweaks for Windows, assorted cleanup.
Switch to optimized Logger().
Require calibre 1.28 - changes to libiMobileDevice:listdir() pattern.
Recover from zip error when zip file created under different OS.
Silence ios.exists() calls to libiMobiledevice when fetching covers, polling for connected status, looking for booklist.zip.
Require calibre 1.29 (libimobiledevice 'silent' switch). Diagnostic tweaks.
Diagnostic tweaks. Cache booklist.zip from sync_booklists().
Use sync_booklists() to rewrite cached booklist.zip after I/O with device.
Raise InitialConnectionError if connect_idevice() fails. Shows up in debug trace regardless of plugin debug log settings.
Support metrics logging
Added BBEdit file markers for version, minimum calibre version