Fixes the priority of defaults -> configfile -> cli arguments
Fixes the priority of defaults -> configfile -> cli arguments

(cherry picked from commit a55a8abd4d643c9875687cbc32e3f5a983431a55)

Conflicts:
	config.go

tianon/boot2docker-cli,mattrobenolt/boot2docker-cli,nathanleclaire/boot2docker-cli,beni55/boot2docker-cli,boot2docker/boot2docker-cli,mattrobenolt/boot2docker-cli,boot2docker/boot2docker-cli,beni55/boot2docker-cli,moxiegirl/boot2docker-cli,nathanleclaire/boot2docker-cli,vmware/boot2docker-cli,tianon/boot2docker-cli,vmware/boot2docker-cli,SvenDowideit/boot2docker-cli,moxiegirl/boot2docker-cli,SvenDowideit/boot2docker-cli