updated IMAPX files as of EDS commit EVOLUTION_DATA_SERVER_3_4_3

* updated the local IMAPX code from upstream
* now at EDS commit
  967212df27ac7cd03f79c237b693200b9df4ef58
Merge branch 'EDS_IMAPX_nobuild-3-4' into gnome-3-4
IMAPX: updated VERSIONS file to new upstream E-D-S commit EVOLUTION_DATA_SERVER_3_4_3
CamelIMAPXExtdServer: updated for upstream fixes

* updated for upstream CamelIMAPXServer fixes
  (#677841, #664639 from upstream master)
NEWS update for 3.4.3 release
post release version bump
configure.ac: relax GMime dependency

* allow GMime 2.6 in addition to 2.4
* GMime is used in the unit tests only
  (and should be replaced by CamelMime)
* building the tests should be made
  optional
docs: updated INSTALL-notes for 3.4
updated IMAPX files as of EDS commit EVOLUTION_DATA_SERVER_3_4_4

* updated the local IMAPX code from upstream
* now at EDS commit
  758371620ef8efef4c2f30902dae55caae17a1f9
Merge branch 'EDS_IMAPX_nobuild-3-4' into gnome-3-4
IMAPX: updated VERSIONS file to new upstream E-D-S commit EVOLUTION_DATA_SERVER_3_4_4
CamelIMAPXExtdServer: updated for upstream 3.4.4 fixes
Doxyfile: updated version information to 3.4.4
NEWS update for 3.4.4 release
post release version bump