Fixes scollTop property that is deprecated on body

Chrome 32 deprecates document.body.scrollTop, should use
document.documentElement.scrollTop instead. Polyfill describe here
https://developer.mozilla.org/en-US/docs/Web/API/Window.scrollY
Style and reduce redundant code
Merge pull request #110 from jwestbrook/cumulativeScrollOffset-fix

Fix use of `scrollTop` property in `Element.cumulativeScrollOffset`.
Fix failing string test in Chrome.
Update Sizzle to latest stable version.
Update include point for latest version of Sizzle.
Remove a failing test.

(Sizzle doesn't seem to support this anymore, which is fine with me because it's a ridiculous selector.)
Change failing tests.

One of these tests presumably tests comma handling — whether we do the right thing when the space is before the comma, or when there end up being duplicate commas — and this is not something we handled before, so if this is a newly-failing test it's because Sizzle used to handle this and now does not. That's fine with me.

The other one appears to be a disagreement over whether `:enabled` should match `input[type=hidden]`, and Sizzle apparently says it does, and I'm OK with that, too.
Fix issue in old versions of IE with checkbox reading.

Some of the tests added in 4a22a5 apparently never worked in old IE. I added a capability check for the buggy behavior and a new path for IE.

Also, changed a `getAttribute` in a test to `readAttribute` — otherwise the test would never pass in IE 6-7, since `getAttribute` doesn't work right.
Add a `test:server` rake task.

For IE, I find it far easier to start the test server on my dev machine, then use my IE machine to visit the test pages manually. For that I need a task that runs the server indefinitely.

At some point I'll add a page that does nothing but list the tests for convenience.
Fix a capability check that raised an exception in IE8.
Bypass a capability check in newer IEs to avoid a "this page uses Java" dialog.
Remove old version of Sizzle in source tree.

The distribution is built with the version in the Sizzle submodule. It's unclear to me that these files were _ever_ used for building a distributable prototype.js.

If there are good reasons to keep them around, I'm happy to hear them. Otherwise they just create confusion.
Bump version number.
Fix issue with `Element.visible` reading only inline style. [closes #131]
Update documentation for `Element.visible`.
Fix regression with handling of `$break` inside `Array#inject`. [close #162]
Fix error in `Element.positionedOffset` that made incorrect adjustments for margins. [close #141]
Fix issue where `getOpacity` would return a string, not a number, in newer versions of IE.

Also fix documentation that incorrectly claimed `getOpacity` was designed to return a string.

[close #116]
Merge pull request #107 from superdav42/master

Add a space when we apply the `alpha` filter in old versions of IE so that we don't disrupt existing filters.