Let the ports tree determine the DISTFILES name
The docbook2mdoc utility is a converter from DocBook V4.x and v5.x XML into
mdoc. Unlike most DocBook utilities, it's a standalone ISC-licensed ISO C
utility that should compile on any modern UNIX system. The only requirement is
libexpat (for parsing XML), which is installed by default on most systems.

WWW: http://mdocml.bsd.lv/docbook2mdoc/
- Correct depends
- Update OSVERSION ranges for clang bug workaround
Update to the 20141116 snapshot of GCC 5.0.

This no longer breaks on FreeBSD 10.0 and later using clang.
Fix warnings.
Resurrect editors/psgml.
Update to 2.0.0-DEV.

PR:	194994
- Add LICENSE.
- Mark CONFLICTS with libotf.

PR:	194984