Box Backup

Add support for optional items in Archives. If the item is not present (the end of the Archive is reached instead) then a default value is returned instead of throwing an exception.

Add missing timeouts to Archive Read() calls.

Fix logging of NamedLock? acquisition for O_EXLOCK method.

Add usage example for -L option, showing how module names were compiled in

Initialise ModificationTime? when uploading complete file.

Add command-line help to test executables.

Fix another test failure on Windows caused by holding files open.

Include full platform name in parcels, to distinguish 64-bit builds.

Fix test script to match change to autoconf variable names.

New 64-bit Windows client build. Based on SVN r3568, built with Cygwin/MinGW64 compiler, tested on Windows 7.