#26 Regular expression search for Notes

By default, Note search is exact.
With option -e, we use regular expression searches:
by default anything containing the @arg argument will match (*arg*)
Alternatively, to specify only notes beginning with arg, we can specify @^arg on the command line.
If the end is desired, we can specify @arg$,
If ^ or $ are part of the note name, we can escape them using the \ escaping character: