CLOUDSTACK-6859:Management Server PermGen run out of memory after some
time due to class leak.

(cherry picked from commit 961cd7657e7dbb69d497123071db3156bd15d8e9)
CLOUDSTACK-6669: Fix support resize in usage server

Signed-off-by: Sebastien Goasguen <runseb@gmail.com>
(cherry picked from commit f0ea44daf12b702ab1deb03d4e6bc3adfab46efc)