DTD versioning again

[Jeff Turner <je...@apache.org>]

The charming topic of DTD versioning needs resolving before 0.3..

See thread:

http://marc.theaimsgroup.com/?t=103984526900003&r=1&w=2


How about adopting the 'catalog symlink' technique:

http://marc.theaimsgroup.com/?l=forrest-dev&m=103995775311610&w=2

Where on each Forrest release, we keep the last digit in synch with the
Forrest version.

So people who explicitly want the Forrest 0.2 DTD would use:

-//APACHE//DTD Documentation V1.1.2//EN

Forrest 0.3 (which might have <acronym> added):

-//APACHE//DTD Documentation V1.1.3//EN

And for 99% of people who don't care as long as the versions aren't
backwards-incompatible, we have:

-//APACHE//DTD Documentation V1.1//EN

which maps to the latest in the 1.1.x DTD series.


This system has the virtue of not requiring effort between releases.
Only after a release (say 0.3) do we need to create a
document-v11-4.{mod,dtd}, and map V1.1.4 and V1.1 to it in the catalog
file.


--Jeff