Simplied the pattern matching for scheduled self-tests. Improved

documentation.  More standard weekday numbering.  Now require that
all 12 characters of the type/date/time string match the given pattern.


git-svn-id: https://smartmontools.svn.sourceforge.net/svnroot/smartmontools/trunk@1335 4ea69e1a-61f1-4043-bf83-b5c94c648137