Update BaseEx.js

This is new version of BaseEx.js supporting IE.

Replaced deprecated functions __defineGetter__, __defineSetter__, __lookupGetter__ with new ECMAScript standards 
(supporting all browsers + IE)
Removed deprecated functions with new ECMAScript standards + support IE
Removed deprecated functions with new ECMAScript standards + support IE

Replaced deprecated functions __defineGetter__, __defineSetter__, __lookupGetter__ with new ECMAScript standards (supporting all browsers + ie)
Change variable name from "a" to "descriptor"
Merge pull request #3 from erayhanoglu/master

This is new version of BaseEx.js supporting IE.