Allow projects to suppress checkstyle warnings

Allow projects to suppress checkstyle warnings

This allows projects to override individual checkstyle rules by
using @SuppressWarnings() annotations. In the example below the
checkstyle error before suppressing the warning is shown and
then the annotation to disable the warning:

(whitespace) MethodParamPad: '(' is preceded with whitespace.

@SuppressWarnings("checkstyle:methodparampad")
public AbstractDataTreeListener (INetvirtSfcOF13Provider provider, Class<T> clazz) {
}

Change-Id: I13cf83a6afca4e8f95e8e2969ebb2ac9129e93f8
Signed-off-by: Sam Hague <shague@redhat.com>