Add option for build is back to normal notifications
Merge commit '4fa23e1'
JENKINS-17297 Plugin hipchat: Not working when sendAs is empty
- check for null is not enough, because it is an empty string
Merge branch 'master' into khan-custom-plugin

Conflicts:
	src/main/java/jenkins/plugins/hipchat/HipChatNotifier.java

No code was altered due to the conflict, which was to default sendAs to
"Build Server" when it was empty or missing. It just required some
merging by hand.