CLOUDSTACK-1221
debian: Require either Java 6 or 7

Our source is 1.6 compatible (pom.xml), but users can choose to compile
with JDK7 and run with JRE 7 if they want.
debian: Copy the 4.2 jar files to the destination directories.

This is FAR from perfect, but it works for now.

the VERSION variable returns 4.1 from the debian/changelog file, but in
the Maven configuration everything is already set to 4.2

So generated JAR files have 4.2.XX-SNAPSHOT in their name.

We probably want to find a better way to match this, extracting the version
somewhere out of Maven maybe?
rat: Fix the license, the mouse is squeaking, Nitin stepped on it :)

Signed-off-by: Rohit Yadav <bhaisaab@apache.org>