sstephenson/dimensions — pull request #7 by javan (2013-11-26 01:23:00+00:00)
Title: Get the dimensions of an unread IO stream by reading ahead

Before:
```ruby
>> Dimensions(File.open("masterpiece.png", "rb")).dimensions
=> nil
```

After:
```ruby
>> Dimensions(File.open("masterpiece.png", "rb")).dimensions
=> [522, 606]
```