Implements #955
- New API /action?action=close
- New Close button
Conflicts:
	src/main/java/com/jaeksoft/searchlib/ClientCatalog.java
	src/main/java/com/jaeksoft/searchlib/web/ActionServlet.java
	src/main/java/com/jaeksoft/searchlib/web/controller/runtime/CommandsController.java
	src/main/webapp/WEB-INF/zul/runtime/commands.zul
Merge pull request #958 from emmanuel-keller/master

Implements #955