Make variable `pr' local to libdriver/input.cc. Based on a patch

Make variable `pr' local to libdriver/input.cc.  Based on a patch
by Bernd Warken <bwarken@mayn.de>.

* src/include/driver.h (pr): Removed.

* src/libs/libdriver/input.cc (pr): New global variable.
(do_file): Deallocate `pr'.
* src/libs/libdriver/printer.cc (pr): Removed.

* src/devices/grodvi/dvi.cc (main), src/devices/grohtml/post-html.cc
(main), src/devices/grolbp/lbp.cc (main), src/devices/grolj4/lj4.cc
(main), src/devices/grops/ps.cc (main), src/devices/grotty/tty.cc
(main): Don't delete `pr'.

* tmac/a4.tmac, tmac/composite.tmac: Use `.do'.
* tmac/papersize.tmac: New file.
* tmac/troffrc: Include `papersize.tmac'.
* tmac/Makefile.sub (NORMALFILES): Add `papersize.tmac'.
* tmac/an-old.tmac: Set LT to LL by default.

* NEWS, MANIFEST, tmac/groff_man.man, man/groff_tmac.man,
doc/groff.texinfo: Updated.

* src/libs/libgroff/paper.cc (add_iso_paper): Fix very embarassing
bug which caused all odd iso papers to have wrong dimensions.

* src/devices/grops/ps.cc (user_paper_width): New global variable.
(main) <'p'>: Set `user_paper_width' also.
(ps_printer::media_width, ps_printer::media_height): Use values
given with option `-p'.