Pull up following revision(s) (requested by spz in ticket #1435):
external/mit/expat/dist/CMake.README: up to 1.1.1.3
external/mit/expat/dist/CMakeLists.txt: up to 1.1.1.3
external/mit/expat/dist/COPYING: up to 1.1.1.2
external/mit/expat/dist/Changes: up to 1.1.1.4
external/mit/expat/dist/MANIFEST: up to 1.1.1.4
external/mit/expat/dist/Makefile.in: up to 1.1.1.4
external/mit/expat/dist/README: up to 1.1.1.4
external/mit/expat/dist/aclocal.m4: up to 1.1.1.3
external/mit/expat/dist/amiga/expat_lib.c: up to 1.1.1.2
external/mit/expat/dist/amiga/expat_vectors.c: up to 1.1.1.2
external/mit/expat/dist/amiga/launch.c: up to 1.1.1.2
external/mit/expat/dist/bcb5/expat.bpr: up to 1.1.1.3
external/mit/expat/dist/bcb5/expat.mak: up to 1.1.1.2
external/mit/expat/dist/bcb5/expat_static.bpr: up to 1.1.1.3
external/mit/expat/dist/bcb5/expat_static.mak: up to 1.1.1.2
external/mit/expat/dist/bcb5/expatw.bpr: up to 1.1.1.3
external/mit/expat/dist/bcb5/expatw.mak: up to 1.1.1.2
external/mit/expat/dist/bcb5/expatw_static.bpr: up to 1.1.1.3
external/mit/expat/dist/bcb5/expatw_static.mak: up to 1.1.1.2
external/mit/expat/dist/bcb5/xmlwf.bpr: up to 1.1.1.3
external/mit/expat/dist/bcb5/xmlwf.mak: up to 1.1.1.2
external/mit/expat/dist/configure: up to 1.1.1.4
external/mit/expat/dist/configure.ac: up to 1.1.1.2
external/mit/expat/dist/conftools/config.guess: up to 1.3
external/mit/expat/dist/conftools/config.sub: up to 1.3
external/mit/expat/dist/conftools/install-sh: up to 1.1.1.4
external/mit/expat/dist/conftools/ltmain.sh: up to 1.1.1.4
external/mit/expat/dist/doc/expat.png: up to 1.1.1.2
external/mit/expat/dist/doc/valid-xhtml10.png: up to 1.1.1.2
external/mit/expat/dist/doc/xmlwf.1: up to 1.1.1.3
external/mit/expat/dist/doc/xmlwf.sgml          delete
external/mit/expat/dist/doc/xmlwf.xml: up to 1.1.1.1
external/mit/expat/dist/examples/elements.c: up to 1.1.1.3
external/mit/expat/dist/examples/outline.c: up to 1.1.1.2
external/mit/expat/dist/expat_config.h.in: up to 1.1.1.4
external/mit/expat/dist/lib/expat.dsp: up to 1.1.1.3
external/mit/expat/dist/lib/expat.h: up to 1.1.1.4
external/mit/expat/dist/lib/expat_external.h: up to 1.1.1.2
external/mit/expat/dist/lib/expat_static.dsp: up to 1.1.1.3
external/mit/expat/dist/lib/expatw.dsp: up to 1.1.1.3
external/mit/expat/dist/lib/expatw_static.dsp: up to 1.1.1.2
external/mit/expat/dist/lib/internal.h: up to 1.1.1.2
external/mit/expat/dist/lib/xmlparse.c: up to 1.6
external/mit/expat/dist/lib/xmlrole.c: up to 1.1.1.3
external/mit/expat/dist/lib/xmltok.c: up to 1.3
external/mit/expat/dist/lib/xmltok_impl.c: up to 1.5
external/mit/expat/dist/m4/libtool.m4: up to 1.1.1.3
external/mit/expat/dist/m4/ltoptions.m4: up to 1.1.1.3
external/mit/expat/dist/m4/ltsugar.m4: up to 1.1.1.2
external/mit/expat/dist/m4/ltversion.m4: up to 1.1.1.3
external/mit/expat/dist/m4/lt~obsolete.m4: up to 1.1.1.2
external/mit/expat/dist/tests/chardata.c: up to 1.1.1.3
external/mit/expat/dist/tests/minicheck.c: up to 1.1.1.2
external/mit/expat/dist/tests/minicheck.h: up to 1.1.1.3
external/mit/expat/dist/tests/runtests.c: up to 1.1.1.3
external/mit/expat/dist/tests/xmltest.sh: up to 1.2
external/mit/expat/dist/win32/README.txt: up to 1.1.1.3
external/mit/expat/dist/win32/expat.iss: up to 1.1.1.4
external/mit/expat/dist/xmlwf/codepage.c: up to 1.1.1.2
external/mit/expat/dist/xmlwf/readfilemap.c: up to 1.1.1.3
external/mit/expat/dist/xmlwf/xmlfile.c: up to 1.1.1.2
external/mit/expat/dist/xmlwf/xmlwf.c: up to 1.1.1.4
external/mit/expat/dist/xmlwf/xmlwf.dsp: up to 1.1.1.3
external/mit/expat/lib/libexpat/expat_config.h: up to 1.4
Update expat to 2.2.0, fixing CVE-2016-0718, CVE-2016-4472,
CVE-2016-5300, and CVE-2012-6702.

(snj)