Bug 13549 - Add a Gtk3 backend for Aiksaurus. Still needs to fix warnings, but seems things work.

Cherry-pick from trunk@33959. By jbrefort

git-svn-id: svn+ssh://svn.abisource.com/svnroot/abiword/branches/ABI-3-0-0-STABLE@33980 bcba8976-2d24-0410-9c9c-aab3bd5fdfd6
Bug 13605 - Use GsfInputHTTP for URLs starting with "http://" or "https://". Helps with #13605 (also needs a fix in libgsf).

Cherry-pick from trunk@33977. By jbrefort

git-svn-id: svn+ssh://svn.abisource.com/svnroot/abiword/branches/ABI-3-0-0-STABLE@33981 bcba8976-2d24-0410-9c9c-aab3bd5fdfd6
Bug 13539 - Correctly escape links in odt exporter.

Cherry-pick from trunk@33978. By jbrefort.

git-svn-id: svn+ssh://svn.abisource.com/svnroot/abiword/branches/ABI-3-0-0-STABLE@33982 bcba8976-2d24-0410-9c9c-aab3bd5fdfd6
Fix linkage for libjpeg.

git-svn-id: svn+ssh://svn.abisource.com/svnroot/abiword/branches/ABI-3-0-0-STABLE@33983 bcba8976-2d24-0410-9c9c-aab3bd5fdfd6
Bug 13605 - Fix UT_go_url_resolve_relative().

Backport form trunk@33872. By jbrefort

git-svn-id: svn+ssh://svn.abisource.com/svnroot/abiword/branches/ABI-3-0-0-STABLE@33984 bcba8976-2d24-0410-9c9c-aab3bd5fdfd6