Revert changes which broke backwad compatibility based on discussion in jenkins-dev list
Revert javadoc too.
Revert changes in method encode too.
Merge branch 'revert-ampersand-encoding' of https://github.com/lvotypko/jenkins into pull683

Conflicts:
	core/src/test/java/hudson/UtilTest.java
Added changelog record for pull683
Merge remote-tracking branch 'jenkins/master'