Improves methods, adds the global function
Adds support for fatal errors
Uses [result, err] as the standard for error catching
Fixes classcalc, Tests errors
Fixes more classcalc, Tests errors
Fixes invalid Tests
Improves debug output, fixes Tests
Fixes yet more invalid Tests
Fixes yet another Tests error
Fixes an invalid test
Improves error handling, testing
Improves global setting, tests
Improves len, float, int for classes, instances
Ensures an error is raised on an invalid set

Also fixes a small typo.
Prevents attempting to set when inside

Also adds reqargs to `is`.
Fixes set recognition, funcfloat reqargs, tests