update junit test classes and there dependencies

pom.xml

...ava/net/sourceforge/plantuml/servlet/OldProxyServlet.java

...n/java/net/sourceforge/plantuml/servlet/ProxyServlet.java

src/main/webapp/index.jsp

...t/java/net/sourceforge/plantuml/servlet/TestAsciiArt.java

...st/java/net/sourceforge/plantuml/servlet/TestCharset.java

...test/java/net/sourceforge/plantuml/servlet/TestCheck.java

src/test/java/net/sourceforge/plantuml/servlet/TestEPS.java

src/test/java/net/sourceforge/plantuml/servlet/TestForm.java

...test/java/net/sourceforge/plantuml/servlet/TestImage.java

...t/java/net/sourceforge/plantuml/servlet/TestLanguage.java

src/test/java/net/sourceforge/plantuml/servlet/TestMap.java

...t/java/net/sourceforge/plantuml/servlet/TestOldProxy.java

...test/java/net/sourceforge/plantuml/servlet/TestProxy.java

src/test/java/net/sourceforge/plantuml/servlet/TestSVG.java

...test/java/net/sourceforge/plantuml/servlet/TestUtils.java

...java/net/sourceforge/plantuml/servlet/WebappTestCase.java

...rceforge/plantuml/servlet/server/EmbeddedJettyServer.java

...t/sourceforge/plantuml/servlet/server/ExternalServer.java

.../net/sourceforge/plantuml/servlet/server/ServerUtils.java