Improves OpenGL-ES support (especially for Raspberry Pi), contribution of Erkki Nokso-Koivisto, fetches the GLSL version correctly when using ES2

git-svn-id: https://jmonkeyengine.googlecode.com/svn/trunk@10300 75d07b2b-3a1a-0410-a2c5-0572b91ccdca

engine/src/jogl/com/jme3/renderer/jogl/JoglRenderer.java

@@ -160,7 +160,7 @@ public class JoglRenderer implements Renderer {
         }
 
         String versionStr = null;
-        if (caps.contains(Caps.OpenGL20)) {
+        if (caps.contains(Caps.OpenGL20) || gl.isGL2ES2()) {
             versionStr = gl.glGetString(GL2ES2.GL_SHADING_LANGUAGE_VERSION);
         }
         if (versionStr == null || versionStr.equals("")) {