Added Array.prototype.merge()

This adds a merge shortcut so that you are able to easily add two
seperate arrays together.  This both alters the array and returns
the new array value.
Added test HTML page.

Adds a test for each extension, leaving an example on the page.
Added JS for test page.

Checks for presence of added extensions and displays the output of
each on the page.  Will display a false-y value if not present.