LimitStream::seek() now expects offset in the wrapping, not the wrapped stream.
Merge pull request #23 from checat/fix-limitstream-seek

Fix LimitStream::seek() to accept relative offset
Work for 3.0
Adding back a deprecated MetadataStreamInterface
Cleaning up the getMetadata function
A little cleanup
Clarifying changelog;
Minor interface changes, async, and buffers
Cleaning up and adding more docstrings
Clarifying write() return value
Removing some temp variables
Updating constructor and factory method for streams

Removed the size argument, and replaced it with an associative
array of options, including "size" and "metadata" that can be used
to add custom metadata to the stream.
Minor cleanup
Adding information about the on_write return value
Removing unnecessary check
Changing on_write to write for consistency