Adds interpretation of ordinary Python character escapes (like "\t") and
a special escape to fetch a particular Git version of a file, in double-quoted
strings used as the FILENAME argument of a {! ... !} inclusion directive.
Resolves#11.
Resolves#12.
Co-authored-by: Glen Whitney <glen@studioinfinity.org>
Reviewed-on: #13
Co-Authored-By: Glen Whitney <glen@nobody@nowhere.net>
Co-Committed-By: Glen Whitney <glen@nobody@nowhere.net>