Modified the Formatter.setContextualUnit method in a way that allow us to set the unit even when we do not know the quantity type.
Miscallaneous correction in javadoc and added/moved tests.


git-svn-id: https://svn.apache.org/repos/asf/sis/branches/JDK7@1569683 13f79535-47bb-0310-9956-ffa450edef68