LabyModel limit public constructors to

LabyModel(MazeParams params, Random random)
and
 LabyModel(String pFormat, InputStream pIn)

fix unchecked and (java9) deprecated Short(short)

build.xml

@@ -22,6 +22,7 @@
     <!-- Compile the java code from ${src} into ${build} -->
     <javac srcdir="${src}" destdir="${build}" includeantruntime="false" classpath="libs/${artgraphicslib}.jar">
       <exclude name="org/artisanlogiciel/games/javafx/*"/>
+      <compilerarg value="-Xlint:deprecation,unchecked" />
     </javac>
   </target>