Fixed feature detection in Webkit and global decl.

[udondan]

Fixed #22 and #24 and changed Blob declaration to method of window object (=global), which makes it work in Meteor environment.

Tested on:

OS X:

• Opera 11.62
• Opera 21.0
• Safari 7.0.3
• Chrome 35.0
• Firefox 3.6
• Firefox 10.0.4
• Firefox 29.0.1

iOS 7:

• Safari
• Opera mini 7.0.5
• Opera Coast 3.0.1
• Chrome 30.04

Windows 7:

• Safari 5.1.7
• IE 9

[eligrey]

Thanks for contributing :smile:

[eligrey]

Does self work in place of window for you in Meteor? If you've seen my code before, you'll see that I prefer self as it also works in workers.

[udondan]

Thanks for merging :). And yes, self works in Meteor, which I didn't expect. Just tested it.