core: Add dependency to original sfl4j library

1) Adds org.slf4j module into tools category which will provide original
   slf4j-api.jar and slf4j-jdk14.jar so we can use slf4j in standalone
   tools with java.util.logging backend
2) Adds dependency to slf4j package

Change-Id: I12a3fc298ec3d641e86ea5e766e7e7aa86690b14
Bug-Url: https://bugzilla.redhat.com/1109871
Signed-off-by: Martin Perina <mperina@redhat.com>