Plus42 Equations, Preview Release

[Thomas Okken]

New update:

1. Added a menu to the R↓ key, with REGX, REGY, REGZ, REGT, and STACK.
2. Added STAT menu.
3. Fixed equation leak in PRP/TRACE.
4. Moved the ":" from Shift-÷ to Shift-R/S
5. Made the decimal key produce "." or "," depending on RDX./RDX, mode and whether Shift is pressed or not.
6. Mapped RCOMPLX and PCOMPLX to Shift-STO, depending on RECT/POLAR mode
7. Mapped ∫ to Shift-8.