Add cron match time function

In addition to the normal time functions (see #141) we should be able to do
`lambda: cronMatch('* 8-17 * * * *', "time")` to greatly simplify and time based expressions one would write.

Read issue #141 and locate the existing normal time functions and expression evaluation entry points. Trace how a lambda expression receives its arguments, then define the expected behavior for cronMatch('* 8-17 * * * *', "time"). Done means cron-based time expressions work as described and existing time-function behavior remains intact.

Written by the indexing model from the issue text.