Merge pull request #55 in ZP/z-push from bugfix/ZP-702-Attachments-are-1-or-2-bytes-short to develop

* commit 'bb60677f':
  ZP-702 Implement seeking capability to MAPIStreamWrapper. Add stream
size to log output.
  ZP-702 Attachments are 1 or 2 bytes short. Released under the Affero
GNU General Public License (AGPL) version 3. Fixed empty attachment data
written, because stream was not at the beginning eg. by a previous call
to fstat. Also logging now number of bytes written and not length of
stream, to be able to detect similar problems.
  ZP-702 Implement plain and base64 encoded stream support into the
wbxml encoder and streamer. Removed padding filter and added a
null-char-replace filter used when streaming plain streams (tested but
not part of this ticket).
  ZP-702 Attachments are 1 or 2 bytes short if size is not 3 byte
aligned. Released under the Affero GNU General Public License (AGPL)
version 3.

(cherry picked from commit 64f7bbb2)

Conflicts:
	src/lib/wbxml/replacenullcharfilter.php