#12 Support strings better

[Jude Nagurney]

The current implementation currently accepts anything
between single quotes as a string. The v1.4, and the
v1.3 syntax for that matter, specify that newlines,
tabs, formfeeds and a couple other characters shouldn't
be in the string, and should be specified via c-style
blackquoting instead. There also appears to be support
for specifying octal characters via \[0-7][0-7][0-7]