Here's a rough list of future ideas for B-em.  Not in any particular order.

* [ ] A better support for Control key.  It is tricky to remap it to any key.
* [x] Return to emulator after hard reset; currently stays in meny mode.
* [ ] Toggle for full-throttle mode.
* [ ] Add current speed indicator for emulation speed.
* [ ] Write to a FAT disc image for Master 512 emulation.
* [ ] Better timing for 32016 emulation.
* [ ] Support to other ROM configuration, e.g. Torch Co-Pro.
* [ ] Transition to GLFW
* [ ] String-handling audiot
* [ ] `tree.h` as standard?
* [ ] gindent(1)
