Removed the IPT_POKER_BET, replacing it with IPT_GAMBLE_BET.
Re-organised the order of input types in the source and the
documentation to better reflect how they're logically grouped or
organised on a mahjong or gambling control panel.
Made the blackjack, poker and slots documentation headings subheadings
under the gambling heading.
Cleaned up inputs for a number of gambling games.
* Docs: Overhaul the default keys list
* Second phase of documenting default inputs better, also change Score to Take Score in Mahjong inputs
* Phase two of default keys docs adjustment.
- reset scheduler savestate to what it was for years before rewind
-- changing saved variables should be done after thorough testing. right now, adding some vars breaks some machines, adding other vars breaks others
- switch to megabyte-wise capacity
-- savestate size greatly differs between machines, relying on state count is unstable
- switch to internal indexing
-- no longer depends on inaccurate machine time
- rewind accelerator key in debugger (Ctrl+F11)
- report capacity hit (once), with some useful info
- make error reports saner
- mention rewind and rewind_capacity in the docs
