allows Alt-combos on European Amiga keyboards to be restored as MAME
will now prefer the simpler Shift-combos to get characters that can be
typed in more than one way
* move rarely-used output and pty interfaces out of emu.h
* consolidate and de-duplicate forward declarations, also remove some obsolete ones
* clean up more #include guard macros
* scope down a few more things
(nw) Everyone, please keep forward declarations for src/emu in src/emu/emufwd.h -
this will make it far easier to keep them in sync with declarations than having
them scattered through all the other files.
* Fixed Shift-Alt combinations with natural keyboard
* Fixed crash on keyboard inputs with four characters
* Corrected polarity of KB_DATA from Amiga to keyboard
* Completely rewrote 68HC05CxA-based A1200 keyboard device, now working
* Fixed KB_DATA mixing in A500 keyboard
* Made A500 keyboard caps lock LED output name consistent with A1200
* Added Alt- and Alt-Shift- characters to A500 US keyboard
* Fixed natural keyboard modifiers with LLE keyboards
* New abbreviated types are in osd and util namespaces, and also in global namespace for things that #include "emu.h"
* Get rid of import of cstdint types to global namespace (C99 does this anyway)
* Remove the cstdint types from everything in emu
* Get rid of U64/S64 macros
* Fix a bug in dps16 caused by incorrect use of macro
* Fix debugcon not checking for "do " prefix case-insensitively
* Fix a lot of messed up tabulation
* More constexpr
* Fix up many __names
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
