Switched to new JSONL parser

The new parser is generated by Jison (a JS parser generator, like
Bison).
-- Modified one of the Jison samples to support our "leniency"
requirement.
-- Added a makefile to build & minify the parser.
-- The new parser also generates better error messages... but they
expect to be displayed in a console.  So I changed the error alert DIV
to use a fixed-width font.