Function integerTest

Checks if value an integer and meets additional criteria. See numberTest for guard details, or use that if integer checking is not required.

Note:

• bipolar will mean -1, 0 or 1.
• positive: must be at least zero
• negative: must be zero or lower
• aboveZero: must be above zero
• belowZero: must be below zero
• percentage: must be within 0-1, inclusive
• nonZero: can be anything except zero