[libxml2] (3 commits) Non-fast-forward update to branch ddkilzer/reserve-NUL-termiantor-and-report-errors-consistently-in-xmlBuf-xmlBuffer

[David Kilzer <ddkilzer src gnome org>]

The branch 'ddkilzer/reserve-NUL-termiantor-and-report-errors-consistently-in-xmlBuf-xmlBuffer' was changed 
in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  823a427... Reserve byte for NUL terminator and report errors consisten

Commits added to the branch:

  c14cac8... xmlBufAvail() should return length without including a byte (*)
  a6df42e... Fix integer overflow in xmlBufferDump() (*)
  4708164... Reserve byte for NUL terminator and report errors consisten

(*) This commit already existed in another branch; no separate mail sent