Adding some features and fixing some issues

.- Reviewing development checklist: Enabling security management, adding some missing constants, using Liferay's language utilities.
.- Changing label edit to save in text editor. Changing arguments arg0 to event.
.- Using Liferay's multivm pool for loggedUserMap and whiteBoardDump to support clustered deployment.
.- Removing username and user image path from request.
.- Fixing drag and drop capability of the portlet.
.- Using constants for javascript constants.
.- Removing <async-supported> from web.xml because it was preventing deploy the portlet in glass fish bundle.
.- Updating PACl policy.
.- Updating atmosphere libraries to lastest stable version.
.- Adding portlet class to clean cache when portlet is redeployed.
.- Removing initial text in text editor because it was necessary delete it before to write something.
.- Fixing issue with free draw shapes, they were turning black after a reload.
.- Adding line color to freedraw and text.