#1242 CIF JS/HTML codegen: fix real division on integer arguments.

• Best to review per commit.
• End-user visible changes:
  • Fixed JS/HTML code generated for real division (/) on integer arguments where the divisor is never zero. Removed double cast, as it is invalid and also unnecessary in JS.
  • Generated JS/HTML code for the divide utility function has JSDoc improvements.
  • Fixed real overflow error message of the divide utility function for generated JS/HTML code.
• Other changes:
  • JavaScriptRealTypeInfo.getBinaryExpressionTemplate: fixed a Java comment.

Closes #1242 (closed)