Ready fires on IE10 before the document is ready.

Added additional check for document.body into the ready check.
Changing the readyRE regex does resolve the issue on IE, but breaks
Chrome.  Adding this check fixes IE and doesn't seem to have any
problems on Chrome/Firefox.
IIS Mime type for Javascript is "application/x-javascript" not "application/javascript".

The IIS Mime type for javascript does not match either of the two listed
in Zepto.
This causes requests for javascript files to be rejected with a "406 Not
Acceptable".
As much as IIS should use the more standard type, developers will not
necessarily have control over the server.