buildimage via Dockerfile
add buildimage example
buildimage returns a Image structure
fix latest version buildimage bug when content-type is application/json
fix review opinion
delete blank lines
client: fix stream with nil output stream
add purestream function to get response without any opration on the data
parse build result with regular expression
remove blank lines
Merge branch 'master' of github.com:cheneydeng/go-dockerclient
all: gofmt -s -w .
authors: add cheneydeng
example_test: fix year in copyright header
support listeners for events

Change adds two methods to client:

- AddEventListener adds a channel to receive *APIEvents
  If this is the first listener, event monitoring is started.
- RemoveEventListener causes a channel to no longer receive *APIEvents
  If this is the last listener, event monitoring is stopped.