Makefile and template updates, and helper data and scripts

* Moves Z80 and MCS48 and EMUDUMMY into a common makefile
* Adjusts the Cat and Coleco builds to use that common makefile
* Updates the build parameters for IBM 5150
* Change messloader.js to be immediately usable for testing by removing the .gz filename, and by supporting systems which don't require game files to boot
* Adds scripts and data for full makefile dependency resolution
* Adds a blank makefile template supporting the new makefile format
* Adds human-readable dependency data in case the scripts go horribly wrong