Use [].indexOf shim on IE<=8

where [].indexOf is not implemented
Make typeable test compatible with IE<=8

[].indexOf is not defined on IE<=8
old IE support: Replace element.focus with Syn.__tryFocus()

element.focus() will throw in old IE if the element is invisible or
under other conditions.
Remove extra trailing spaces in mouse.support.js
firstElementChild is not supported by IE8
delete window.xxx doesn't work on old IE
setTimeout.apply is undefined in old IE
Fix key codes test on old IE
Merge pull request #50 from rosenfeld/master

Improve support for old IE (<=8)