Documentation corrections

Some, obvious, documentation corrections.

src/net/sourceforge/plantuml/core/ImageData.java

@@ -74,7 +74,7 @@ public interface ImageData {
 	 * <map id="foo_map" name="foo_map">
 	 * <area shape="rect" id="..." href="..." title="..." alt="" coords="64,68,93,148"/>
 	 * </map>
-	 * </code>
+	 * </pre>
 	 * 
 	 * @param nameId the id to be used in the cmap data string.
 	 */

src/net/sourceforge/plantuml/core/UmlSource.java

@@ -204,7 +204,7 @@ final public class UmlSource {
 	 * Check if a source diagram description is empty. Does not take comment line
 	 * into account.
 	 * 
-	 * @return <code>true<code> if the diagram does not contain information.
+	 * @return <code>true</code> if the diagram does not contain information.
 	 */
 	public boolean isEmpty() {
 		for (StringLocated s : source) {

src/net/sourceforge/plantuml/tim/stdlib/LoadJson.java

@@ -62,7 +62,7 @@ import net.sourceforge.plantuml.tim.expression.TValue;
  * Supports three parameters for datasource, default JSON value and charset. The
  * datasource will be checked against the security rules.
  * <p>
- * Examples:</br>
+ * Examples:<br/>
  * 
  * <pre>
  *     &#64; startuml