CLOUDSTACK-6926: removed hard coded jdk dirs and setting java home using readlink and dirname

(cherry picked from commit c468228fe807c621decc5919dadae9bcbb38c753)

Conflicts:
	packaging/debian/init/cloud-usage
CLOUDSTACK-6624: set specifyIpRanges to true if specifyVlan is set to true

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>