Handle MAX() formula expression

[kdinev]

Implement handling for a MAX() formula expression.

Requirements:

• MAX() should evaluate to a number
• MAX() should take as parameters a sequence of values, or value references
  • MAX(1, 2, 3) should yield 3
  • MAX(A1, A2, A3) should yield the maximum of the reference values in elements marked with the corresponding IDs, or data-ref attributes
• MAX() should take as parameters range of values or value references
  • MAX(1 : 3) should yield 3
  • MAX(A1 : A3) should yield the maximum of the reference values in elements marked with the corresponding IDs, or data-ref attributes