syntax for language names (instead of 'string').
createlang now handles the case where a second language uses the same call
handler as an already installed language (e.g., plperl/plperlu).
droplang now handles the reverse case, i.e., dropping a language where
the call handler is still used by another language. Moreover, droplang
can now be used to drop any user-defined language, not just the supplied
ones.
No big deal; fixed lots of other markup at the same time.
Bigest change: make sure there is no whitespace
in front of <term> contents.
This will probably help the other output types too.