[TI83+] Multi-page application support

[dom]

I've recently merged a great contribution from @HeronErin which allows multi-page TI83+ flash applications to be built.

The vectorised TI intra-bank calling mechanism requires a different building mechanism to `__banked` applications on other machines, so please take a look at the example: https://github.com/z88dk/z88dk/tree/mas ... _flash_app However, in general, banked source code can be made portable across multiple targets that support the banked calling convention.

[stefano]

Awesome ! Thankyou for supporting this !
I also wish to thank @HeronErin and all the people trying hard to raise our interest on the evolved TI83+ models.