Motivation:
HttpPostMultipartRequestDecoder threw an ArrayIndexOutOfBoundsException
when trying to decode Content-Disposition header with filename
containing ';' or protected \\".
See issue #3326 and #3327.
Modifications:
Added splitMultipartHeaderValues method which cares about quotes, and
use it in splitMultipartHeader method, instead of StringUtils.split.
Result:
Filenames can contain semicolons and protected \\".