get-bugzilla-attachments-by-mimetype: add libebook types

Change-Id: I963549beb45112504d5edfef169d4970fbec822d
libxml2: upgrade to version 2.9.1

- from libxml2-configure.patch:
  * drop config.sub Android stuff (obsolete)
  * drop Makefile.in disabling targets for Android (hypothetically obsolete)
  * drop xmlversion.h changes (pointless - configure.js generates it)
  * split out libxml2-freebsd.patch.1
  * split out libxml2-config.patch.1
- drop libxml2-long-path.patch (integrated upstream)
- drop libxml2-gnome599717.patch (obsolete)
- drop libxml2-xpath.patch (obsolete)
- drop libxml2-latin.patch (obsolete)
- drop libxml2-aix.patch:
  presumably don't need special check for V7BETA since it's released now
- drop libxml2-mingw.patch:
  actually appears to patch a MSVC-specific part of the file so is
  obsolete anyway

Change-Id: I87bf8968bd4a554852a2791420a5d0db822beeaa