Proposed browser support change.
Provide machinery to use this framework without globals.

Having global shared state is always a bad thing™. So we allow the creation of individual instances of streaming clients, each with their own associated AWS.S3 instance. The new code looks something like:

```javascript
var client = require('s3-upload-stream')(AWS.S3());
var stream = client.upload({
  bucket: "...",
  key: "..."
})
```

Backwards compatibility is also shoehorned so those who are using the library can continue to do so just as they were before.

Version bump accordingly.
fix a few typos
send the multipart upload ID back to client on ready
Add ability to resume multipart uploads.

Adds second optional argument to constructor, `sessionDetails`,
which can receive an UploadId and set of Parts as recorded from
a previous session.

Important: the Parts array must be contiguous and start with 1.
There should be no gaps, as the new part number is calculated from
the length of the array, not by actually looking at the numbers.

On resume, a 'ready' event will be fired just before the first new
part begins uploading, with the resumed UploadId.

Tests included.
Remove debug line
Adds pause() and resume() methods to the S3 upload stream.

Calling pause() will:
* emit a 'pausing' event with the number of mid-upload parts.
* immediately halt stream input, until an internal 'resume' event.
* delay queued up (but not yet sent) parts until the 'resume' event.

Calling resume() will:
* fire the internal 'resume' event
* emit an external 'resume' event

When all mid-upload parts complete, a 'paused' event fires with the
current UploadId and Parts data, suitable for freezing for manual
resumption at a later time.

pause() on a dead or paused stream does nothing (returns false).
resume() on an unpaused stream does nothing (returns false).
also return true on resume under normal circumstances
fix comment, outdated
Add docs for #25
Also send the byte offset back with the paused event.
Merge branch 'izaakschroeder-no-globals' and 'konklone-pausing' into 1.0.6

Conflicts:
	lib/s3-upload-stream.js
Documentation changes and other minor tweaks.