Formula parser optimizations and enhancements.

[JanKallman]

• Optimize tokenizer.
• Reuse tokens for shared formulas.
• Reuse expressions for shared formulas.
• Add colon as operator.
• Add intersect operator (Space)
• Share atomic expressions in shared formulas (constants expressions).
• Support for ranges with operators in function arguments, ex: SUM(A1:B3 + C1:D3)

[JanKallman]

Work in progress in this branch formula_parser_enhancements