DB48X: HP48-like RPL implementation for DM42

[c3d]

Release v0.7.4 of DB48X is now available for DM42 and DM32.

This release is mostly about polishing various aspects of the implementation to make it more convenient and more efficient. It also adds user-defined functions parsing and evaluation, pixel-manipulation commands, bit operations on binary numbers, memory operations like sto+ or incr, loading and saving BMP files, color support in the simulator, and more.

Please give it a whirl and let me know. I'll try to record and publish a video with the new features later today.