Change AttributeKey matching to singleton matching

Removes the ClassTag and makes it impossible to generate imposter keys, forcing a one to (one or none) correspondance between key and entry whereas it had been possible to generate "imposter" keys by using the same name and type.
Update comments to reflect the new reality of key equality.
Fix minor issue with Authorization header parser
Merge pull request #87 from gribbet/master

Fix minor issue with Authorization header parser
Fix bug in EntityDecoder.error

The Task that kills the body is simply ignored, so the body isn't killed.
Merge branch 'master' of https://github.com/http4s/http4s
Fix broken commit and add a test
Add the ability to specify the blaze-client timeout.
Client timeout is now a 'total request' timeout

Previous behavior was for a 'quiet time' timeout. This seems more desirable.
Add ability to specify the ExecutionContext in blaze clients
Remove threading of the timeout in blaze-client

If the timeout is specified per Client object, there is no need to thread the timeout
Rename a spec
Address some naming convention issues
blaze client will now actually timeout on the whole request
Fix some bugs with Http1ClientStage and reuse
Merge ready state of Http1ClientStage into a single atomic reference
Fix blaze body cleanup mechanisms
Move some Exceptions to org.http4s package
Add some tests for Http1ServerStage
Change Status equality to disregard the reason.

The reason is not important to the protocol.