* src/include/posix.h: Remove definition of FILENAME_MAX.

* src/include/posix.h: Remove definition of FILENAME_MAX.

* src/preproc/html2/pre-html.h, pre-html.cc: Add return type to
`sys_fatal' and `stop' function().

* test-groff: Updated.

Added the new troff command .output <arg> to suppress output (while
still obeying motion) and also the opminx, opminy, opmaxx, opmaxy
registers (for passing the output dimensions to the output device).

* src/roff/troff/div.cc (top_level_diversion::output): Use `width'
parameter.
* src/roff/troff/node.h, src/roff/troff/node.cc
(troff_output_file::really_print_line,
ascii_output_file::really_print_line,
supress_output_file::really_print_line): Use `width' parameter.
(troff_output_file::really_on, troff_output_file::really_off,
output_file::on, output_file::off, real_output_file::on,
real_output_file::off, real_output_file::really_on,
real_output_file::really_off): New functions.
(real_output_file:public output_file): New variable `output_on'.
(real_output_file::begin_page, real_output_file::copy_file,
real_output_file::transparent_char, real_output_file::print_line):
Use it.
(real_output_file::print_line): Use check_output_limits.
* src/roff/troff/reg.h, src/roff/troff/request.h,
src/roff/troff/input.cc (assign_registers): New function to remove
two `goto's.
(do_ps_file): Use it.
(check_output_limits, reset_output_registers, output_request,
init_output_requests): New functions.
(init_input_requests): Updated.

Added new grohtml2 device and html2 preprocessor (coding
not yet finished) which will eventually replace grohtml.

* Makefile.in, tmac/Makefile.sub, tmac/eqnrc, tmac/troffrc-end:
Updated.
* src/include/htmlindicate.h, src/include/htmlindicate
(html_begin_suppress, html_end_suppress): New functions.
* src/preproc/tbl/main.cc: Use it.
* src/roff/groff/groff.cc: Add support for html2 device (which will
automatically invoke the html2 preprocessor).
* src/roff/troff/input.cc (is_html2): New variable.
* src/roff/troff/troff.h, src/roff/troff/env.h,
src/roff/troff/env.cc (environment::add_html_tag): New function
(uses `is_html2').
(environment::do_break): Use it.
* font/devhtml2/*: New files.
* src/devices/grohtml2: New device.
* src/preproc/html2: New preprocessor.
* tmac/tmac.html-tags, tmac/tmac.html2: New files.