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.
Add test for loading Javascript and Mime type.

Added tests cases for loading javascript using Ajax and also to check
that the Accept header is being set to the correct list of Javascript
Mime types.
Calling the addClass, removeClass and toggleClass methods without
any arguments or with undefined/null values, now don't freeze
Zepto
Calling the addClass, and toggleClass methods without any arguments
or with undefined/null values, now don't freeze Zepto.
Merge branch 'master' of github.com:RichardOtvos/zepto

Conflicts:
	src/zepto.js
Fixed the bug if the argument was a null value.
Added the scrollLeft functions
Added tests for scrollLeft()
Remove all element data with `el.removeData()`

When calling .removeData() with no arguments, all values that were
previously set using .data() will be removed from the element. Adds
jQuery compatibility.
Merge pull request #833 from RichardOtvos/add-scroll-left

Add scroll left
Don't assume certain strings are numbers in .data(), fixes #852
Fixed spelling typo
Increased the default test timeout.
Merge pull request #857 from nanek/increase-test-timeout

Increased the default test timeout.
Merge pull request #856 from glenselle/patch-1

Fixed spelling typo
Merge pull request #844 from ingmarh/remove-all-data

When calling .removeData() with no arguments, remove all data values on the element
Fix addClass, toggleClass and hasClass with empty or no argument. Closes #831.
Workaround some overly eager CoreText "helpful notes" when PhantomJS runs on OS X Mavericks
Merge pull request #825 from sgtwilko/Ajax-Mime-Type

IIS Mime type for Javascript is "application/x-javascript" not "application/javascript".