0.8.0 - increase performance by 2.5X on 83+SE/84+/84+SE; add SHOW command

• 0.8.0 (2023-12-03)
  • Breaking: Flip the order of polar-rectangular conversion menu function
    (>POL and >REC) so that they are consistent with the HP-42S. I don't
    know why I had them reversed.
    • Y register holds the y or theta value, entered first, and
    • X register holds the x or r value, entered second.
  • Breaking: Flip the order of (X, Y) coordinates of the ATN2 menu
    function, so that they are consistent with the >POL function.
    • Y register holds the y value, which is entered first, then
    • X register holds the x value, which is entered second.
  • Breaking: Change WSIZ to prompt the user for the base word size
    using WSIZ _ _ prompt, instead of using the value in the X register.
    • Solves a major usability problem where the user was forced to enter
      the word size using the currently selected base mode (e.g. HEX or
      BIN). For example, the word size 16 was required to be entered as
      10000 in BIN mode, which was too confusing.
    • See Base Word Size for more details.
  • Bug Fix: Tweak the stack-lift logic so that certain operations
    (RollDown, RollUp, X<>Y) enable stack lift even if the previous command
    was a CLEAR or CLX.
    • The rpnFlagsLiftEnabled was not set properly for RollDown, RollUp,
      X<>Y and potentially other commands.
    • So a CLEAR RollDown RollDown RollDown RollDown followed by a number
      would overwrite the X register, instead of doing a stack lift.
  • Increase execution speed by 2.5X on 83+SE, 84+, 84+SE
    • set CPU speed to 15 MHz when supported by hardware
    • remain at 6 MHz on the 83+
  • SHOW display mode
    • implement "Show" function using 2ND ENTRY on TI keyboard
    • displays all 14 internal digits of the TI-OS floating point number
      • if integer < 10^14: display as integer
      • otherwise: display in scientific notation
    • BASE mode variation
      • BIN mode: display WSIZ digits in groups of 4, using up to 4
        display lines
      • all other BASE modes: display underlying floating point number
    • see SHOW Mode for details
  • BASE input limit
    • limit the number of digits that can be entered in BASE mode to a
      maximum that is appropriate for the selected WSIZ and the baseNumber
      selected by HEX, DEC, OCT and BIN
    • for example, selecting HEX and WSIZ 16 will allow only 4 hex
      digits to be entered
    • see Base Input Digit Limit for
      details
  • HELP pages
    • Add page for CONV functions to show order of (x, y, r, theta)
      variables on RPN stack
    • Add page for STAT functions
    • Add page for NUM functions
    • Add page for various display MODEs