[#6836] Skip full-stack Trac ticket importer test if html2text is not available

Signed-off-by: Cory Johns <cjohns@slashdotmedia.com>
[#6336] Use specific locale instead of system default

Signed-off-by: Tim Van Steenburgh <tvansteenburgh@gmail.com>
Merge branch 'master' of https://git-wip-us.apache.org/repos/asf/incubator-allura