Add documentation to set vector operators

Add documentation to set algebraic operators

Add documentation to sequence operators

Add documentation to logical operators

Add documentation to functional operators

Add documentation to constants

Add documentation to comparison and equality operators

Add documentation to calculus operators

Add documentation to arithmetic operators

Fill out XCTestManifests

Add FunctionsTests.swift

Use isMultiple(of:) instead of modulo operator

Rename tuple members in integral argument

Add overload for integral that takes ClosedRange argument

Add CalculusTests.swift