Improve event counter documentation.

Minor fixes related to namings.

DEVSIX-2932

Author: ars18wrw

kernel/src/main/java/com/itextpdf/kernel/counter/EventCounterHandler.java

@@ -56,7 +56,7 @@ This file is part of the iText (R) project.
  * <p>
  * You can implement your own {@link IEventCounterFactory} and register them with {@link EventCounterHandler#register(IEventCounterFactory)}
  * Or implement {@link EventCounter} and register it with {@link SimpleEventCounterFactory} like this:
- * <code>EventCounterManager.getInstance().register(new SimpleEventCounterFactory(new SystemOutEventCounter());</code>
+ * <code>EventCounterHandler.getInstance().register(new SimpleEventCounterFactory(new SystemOutEventCounter());</code>
  * {@link SystemOutEventCounter} is just an example of a {@link EventCounter} implementation.
  * <p>
  * This functionality can be used to create metrics in a SaaS context.

kernel/src/main/java/com/itextpdf/kernel/counter/IEventCounterFactory.java

@@ -47,7 +47,7 @@ This file is part of the iText (R) project.
  * Factory that can be registered in {@link EventCounterHandler} and creates a counter for every reader or writer class.
  * <p>
  * You can implement your own counter factory and register it like this:
- * <code>EventCounterManager.getInstance().registerCounter(new SystemOutEventCounterFactory());</code>
+ * <code>EventCounterHandler.getInstance().register(new SystemOutEventCounterFactory());</code>
  * <p>
  * {@link SystemOutEventCounterFactory} is just an example of {@link IEventCounterFactory} implementation.
  * It creates {@link SystemOutEventCounter} that writes info about files being read and written to the {@link System#out}

kernel/src/main/java/com/itextpdf/kernel/log/ICounterFactory.java

@@ -47,7 +47,7 @@ This file is part of the iText (R) project.
  * Factory that can be registered in {@link CounterManager} and creates a counter for every reader or writer class.
  * <p>
  * You can implement your own counter factory and register it like this:
- * <code>CounterManager.getInstance().registerCounter(new SystemOutCounterFactory());</code>
+ * <code>CounterManager.getInstance().register(new SystemOutCounterFactory());</code>
  * <p>
  * {@link SystemOutCounterFactory} is just an example of {@link ICounterFactory} implementation.
  * It creates {@link SystemOutCounter} that writes info about files being read and written to the {@link System#out}