fix typos
o fix typo in description for "gnu" category (send-pr.1)
o fix partially untranslated sentense in description for "trap" (sh.1)
o fix Japanese wording (stty.1,
o remove extraneous ".Fl )" after "-c class" description (su.1)
o add missing right parren for VGA_WIDTH90 option description (vidcontrol.1)

Submitted by: Satoru Koizumi <koizumi@cms.phys.s.u-tokyo.ac.jp>