Bug 64419 Tomcat example does not need "web app root" attribute
The Tomcat/JSP launching example currently requires the user specify a "web app root" on the main tab. However, all we need is the project (in order to compute a classpath for extra java files and source lookup path). We used to require the attribute for source lookup.
org.eclipse.jdt.ui.examples.javafamily/src/org/eclipse/jsp/launching/TomcatLaunchDelegate.java
/**
	 * Identifier for Tomcat launch configurations.
	 */
	public static final String ID_TOMCAT_LAUNCH_CONFIGURATION_TYPE = "org.eclipse.jsp.TomcatConfigurationType"; 
	
	/**
	 * Identifier for Tomcat classpath provider.
	 */
	public static final String ID_TOMCAT_CLASSPATH_PROVIDER = "org.eclipse.jsp.tomcatClasspathProvider"; 
		
	/**
	 * Launch configuration attribute - value is path to local installation of Tomcat.
	 * The path may be encoded in a launch variable.
	 */
	public static final String ATTR_CATALINA_HOME = "org.eclipse.jsp.CATALINA_HOME"; 
	
	/**
	 * Launch configuration attribute - value is a workspace relative path to the root
	 * folder of a web application.
	 */
	public static final String ATTR_WEB_APP_ROOT= "org.eclipse.jsp.WEB_APP_ROOT"; 	
	/**
	 * Constructs a new launch delegate
	 */
	public TomcatLaunchDelegate() {