Bug 53327 [Progress] Second manual build should optionally cancel the first
M7 If you select a Rebuild All from the workbench this is now run in the background. If it is run again then the user should be prompted to cancel either the new one or the one running. We should also have a "don't ask me again" option.
bundles/org.eclipse.ui.ide/extensions/org/eclipse/ui/actions/GlobalBuildAction.java
this(workbench.getActiveWorkbenchWindow(), type);
	if (shell == null) {
		throw new IllegalArgumentException();
	}
}
/**
 * Creates a new action of the appropriate type. The action id is 
 * <code>IWorkbenchActionConstants.BUILD</code> for incremental builds
 * and <code>IWorkbenchActionConstants.REBUILD_ALL</code> for full builds.
 *
 * @param window the window in which this action appears
 * @param type the type of build; one of
 *  <code>IncrementalProjectBuilder.INCREMENTAL_BUILD</code> or 
 *  <code>IncrementalProjectBuilder.FULL_BUILD</code>
 */
public GlobalBuildAction(IWorkbenchWindow window, int type) {
	if (window == null) {
		throw new IllegalArgumentException();
	}
	this.workbenchWindow = window;
	setBuildType(type);
}
/**
 * Sets the build type.
 * 
 * @param type the type of build; one of
 *  <code>IncrementalProjectBuilder.INCREMENTAL_BUILD</code> or 
 *  <code>IncrementalProjectBuilder.FULL_BUILD</code>
 */