Use standard uint64_t, uint32_t, uint16_t or uint8_t instead of UINT64, UINT32, UINT16 or UINT8
also use standard int64_t, int32_t, int16_t or int8_t instead of INT64, INT32, INT16 or INT8
This is a redo of the split first submitted in #137, with the following differences:
* The newly refactored rom_entry data structure is used
* I've kept the refactored softlist code in src/emu, in order to defer the mechanical process of moving it
* I've kept includes of softlist[_dev].h out of diimage.h, so that changes to either do not trigger an emu.h recompilation
* Obviously, this goes against the latest master