Fix prompt value in IE8
Fix more issues with extra whitespace in IE8 test results
More explicit value setting for Select tests
More IE whitespace handling
Improved handling of selects in RenderBuffer

Previously we were blacklisting selects as root level elements in the
RenderBuffer on IE 8. This allows them to be used after all.
Fix precompilation test in IE
Fix Select test to append to right place
Override JSHint's Object.create stub

JSHint's Object.create stub doesn't pass Ember tests. This adds a flag
to force Ember to stub Object.create.
Removed stray console.log
Fixed some tests for IE9
Better innerHTML handling for IE9
In tests, append to qunit-fixture, not body
Fix failing XSS test in Firefox
Fixes: Safari's 'double finally on error bug'

Bug Demo: http://jsbin.com/usoquy/1/edit
known to be an issue in:
* Safari 6.0.2
* iOS 6 mobile safari
* maybe others

Turns out certain versions of safari 6.0.2 and
potentially other webkits, will execute finally twice,
if an error in finally is thrown. Interestingly the
error will only be thrown once. But the code up until
the error is thrown, will be executed twice.

Although strange, it is rare during normal ideal execution
that this causes real issues, but when it does, it
is quite frustrating to debug.

Two new utility methods provide the 'safe' workaround:

Ember.tryFinally(tryable, finalizer);
Ember.tryCatchFinally(tryable, catchable, finalizer);

These helpers try to abide by the languages try/catch/finally
semantics.
Reorganize mixins and mergeMixins
Remove __emberproto__
Remove __ember_count__ and cloneDescriptor
Merge pull request #1617 from stefanpenner/try_finally_safari_bug

Fixes: Safari's 'double finally on error bug'
Clear up super generation
[Fixes #1621] CoffeeScript _super var conflicts with assertion