Bug 95311 [javadoc wizard] Allow setting of -source 1.5 through UI
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javadocexport/JavadocTreeWizardPage.java
private boolean validDocletPath(String docletPath) {
		StringTokenizer tokens= new StringTokenizer(docletPath, ";"); 
		while (tokens.hasMoreTokens()) {
			File file= new File(tokens.nextToken());
			if (!file.exists())
				return false;
		}
		return true;
	}
	/**
	 * Finds the most severe error (if there is one)
	 */
	private IStatus findMostSevereStatus() {
		return StatusUtil.getMostSevere(new IStatus[] { fJavadocStatus, fPreferenceStatus, fDestinationStatus, fDocletStatus, fTreeStatus, fWizardStatus });
	}
	public void init() {
		updateStatus(new StatusInfo());
	}
	public void setVisible(boolean visible) {
		super.setVisible(visible);
		if (visible) {
			doValidation(STANDARDSTATUS);
			doValidation(CUSTOMSTATUS);
			doValidation(TREESTATUS);
			doValidation(PREFERENCESTATUS);
			doValidation(JAVADOCSTATUS);
		}
	}
}