Switch to DBMC? (road to macros?)

[waywardmonkeys]

"DBMC" is the "Dylan-Based Mindy Compiler" and is a stripped down version of the Gwydion Dylan d2c front-end. It supports macros and other things that the currently Mindy compiler does not. It needs to be able to be built with mindy and completed.

At the least, remaining work includes getting it to build, adding the missing libraries that it needs to Mindy, and writing the code to generate the bytecode files from the in-memory datastructures.

(Each of those can probably be managed by separate bugs with this one observing the entire process.)