BUG-579: Minor code style improvements to eliminate eclipse warnings.

Made inner node implementations private static final in builders.
Removed unused imports.
Removed unused variable declarations.

Change-Id: I33c4840cf56473264c06df63326594af97a23089
Signed-off-by: Martin Vitez <mvitez@cisco.com>
(cherry picked from commit 5794bed73531e9965287b6d0f20308791b5bfb70)
Merge "BUG-579: Minor code style improvements to eliminate eclipse warnings." into stable/hydrogen