core: Removed JDK7 ConfigurationException ctor

Removed ConfigurationException(String, Throwable, boolean, boolean).
This constructor was introduced to RuntimeException in JDK7, and having
it in the common project breaks JDK6 compatibility required for GWT
compilation.

Change-Id: I057c641a8f05b789bb69e15d524588ba3f0f42fd
Signed-off-by: Allon Mureinik <amureini@redhat.com>