Fixed bug where the flag and version bytes where not being correctly wri...

The bug fix for this bug here (https://bugzilla.gnome.org/show_bug.cgi?id=658920) introduced a problem where the Version and Flags bytes (4 in total) required by the spec (https://developer.apple.com/library/mac/#documentation/QuickTime/QTFF/Metadata/Metadata.html#//apple_ref/doc/uid/TP40000939-CH1-SW1) were not written out in AppleAdditionalInfoBox resulting in dash tags which could not be read correctly.

This pull request fixes that problem, and hopefully preserves the originally bug fix (the test still passes).