Remove workaround for ancient HTML generation code.

Merge riastradh-drm2 to HEAD.

Use Mt for email addresses.

branches: 1.8.2; 1.8.4;
Use Lk macro when dealing with URLs. Another part of PR/29238.

branches: 1.7.6;
Use .In instead of .Ar Pa

Remove redundant physical markup. Don't workaround ancient macro argment
limit with .Xo/.Xc.

branches: 1.5.34;
backout the changes made on 29th of january:
- remove gzopenfull() and gzdopenfull()
- un-bump minor number
- remove docs for gone functions.

traditionally this is an invalid change (removing an API from a library
without bumping the major.) it has been decided that this case is special
enough not to require that. no one should have been using these new
functions yet.

PS: this may cause "make install" to barf about older libraries already
being installed.

branches: 1.4.2;
Call it Adler-32 consistently. From jmc@openbsd.

Use -literal instead of -unfilled Bds; replace OpenBSD with .Ox;
<> -> \*[Lt]\*[Gt].

add two functions to zlib: gzopenfull() and gzdopenfull() that both take
additional "const char *savename" and "u_int32_t mtime" parameters that
are written out into the gzip header in the mtime field and as the original
filename.

Add zlib(3) provided by jmc@openbsd -- thank you!