fixed the bug, where null pointer exception may occurred by refreshing workspace.

refs 180

org.fortiss.tooling.kernel/trunk/src/org/fortiss/tooling/kernel/internal/storage/eclipse/EclipseResourceStorageProvider.java

@@ -179,7 +179,19 @@ public class EclipseResourceStorageProvider implements
 							&& isLoaded(file)) {
 						unloadContext(file);
 					} else if (changeKind == IResourceDelta.CHANGED) {
-						handleChange(file);
+						if (isLoaded(file)) {
+							handleChange(file);
+						} else {
+							try {
+								loadContext(file);
+							} catch (IOException ioex) {
+								LoggingUtils
+										.error(ToolingKernelActivator
+												.getDefault(),
+												"Had an error during reloading the file!",
+												ioex);
+							}
+						}
 					}
 
 					// Refresh the top-level elements