MFC r318175:

MFC r318175:

procstat(1): clarify the Signal Disposition section

- Fix a typo (SIGIGN -> SIG_IGN). Use .Dv when referencing SIG_IGN.
- Use semi-colons as soft breaks when separating sentences for
  the FLAGS section.
- Tweak wording for C slightly to flow better and to be a bit
  more technically correct (signals with handlers installed will
  be caught by the target program).
- Reference signal(3) in the SEE ALSO section.

git-svn-id: svn://svn.freebsd.org/base/stable/10@319374 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f