#i125145# build helpcontent only for enabled languages

and treat AOO's default language en-US as always enable to allow that languages
with only partially translated helpcontent can be used with the default language
as fallback.


git-svn-id: https://svn.apache.org/repos/asf/openoffice/trunk@1604826 13f79535-47bb-0310-9956-ffa450edef68