changed (typeof foo !== 'undefined') to (foo !== underfine)

* shorten the test cases for all but first 2 instances than check for global vars
* in some browser this can be a lot faster too (80% on Edge)
https://jsperf.com/type-of-undefined-vs-undefined/30
* shorter notation. in some case just if (foo) as we should check for null as well
(if there are not 0 number cases)

ran all tests and demos. no issues.

Author: Alain Dumesny