Since r254974, periodic scripts' period can be configured
independently.  There is no reason to leave their options
with the daily ones, so move them to their own section.
Move periodic scripts' options into their own section.  Since r254974,
Since r254974, periodic scripts' period can be configured
independently.  There is no reason to leave their options
with the daily ones, so move them to their own section.
Document SIGLIBRT in signal(3); take a stab at the signal description as
the original committer didn't provide one.

MFC after:	3 days