testProps  + createElement fixes for IE7

When iterating over array in IE7 using for ( i in array ) construction, 'i' variable not only takes indices values, but also functions belonging to Array object. For this reason, Modernizr simply fails on a certain tests on IE7.
Also there is an issue with document.createElement invocation on IE7. Its type is for some odd reason an "object", therefore it doesn't have apply() function on it. I hit this issue when using browsernizr2 NPM package, which is a thin wrapper over Modernizr to make it working with browserify.
can you cache `props.length` and loop against that?