refact(ngClass): improve performance through bitwise operations

Change modulo % 2 operations to bitwise & 1
Read about this in Nicholas C. Zakas book "High Performance JavaScript"(ISBN: 978-0-596-80279-0)
Use the Fast Parts --> Bitwise Operators --> Page 156++
Proven at http://jsperf.com/modulo-vs-bitwise/11
test(browser/compile): fix calls to Jasmine fail()

The fail() function in Jasmine expects an Error object parameter.
Also, there is no global alias for fail() so it must be accessed using
`this.fail(new Error())`.
fix(jqLite): correct implementation of mouseenter/mouseleave event

Implement mouseenter/mouseleave event referring to
http://www.quirksmode.org/js/events_mouse.html#link8 and jQuery source
code(not dependent on jQuery).
The old implementation is wrong. When moving mouse from a parent element
into a child element, it would trigger mouseleave event, which should not.
And the old test about mouseenter/mouseleave is wrong too. It just
triggers mouseover and mouseout events, cannot describe the process of mouse
moving from one element to another element, which is important for
mouseenter/mouseleave.

Closes #2131, #1811