Too late for Valentines Day

• Add escape-code sequence for 32-bit Unicode. Issue #48.
• Correct Infix and Tilde character symbols
• Support double backslash (\\) as a single backslash character (\).
• Correct Unicode for ScriptN and ScriptCaptialN
• Correct a number of is-letter-like entries.
• Accept \u21A6 as symbol for Function.
• Change the precedence of |->(Function symbol) to 800 so it isn't interpreted as a |
  followed by ->
• ASCII operator tables can now be generated
• Add DifferentialD and Integrate even though we don't have a full set of prefix operators.
• more precedence values added to operators
• Python 3.11 operation verified