core: change logging from warn to err

Fix bug 879322 make a statement logged in err instead of warning.
In addition, remove unused constant and rename private methods according
to java conventions.

Change-Id: Ia853f5a3ef3e4e364d3c98807d3d1b35e094894e
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=879322
Signed-off-by: Alissa Bonas <abonas@redhat.com>