[ALOY-1087] baseController in widgets should look for local controller

When you try to define a baseController for a widget controller:

exports.baseController = 'foo';

The compiled widget controller will have:

require("alloy/controllers/foo').apply(this, Array.prototype.slice.call(arguments));

Using WPATH('foo') will only make things worse and result in a path like alloy/controllers/my.widget/foo. Related code: - https://github.com/appcelerator/alloy/blob/6e5496c545d67a4fe60bd967bda55a06d5807611/Alloy/template/component.js#L18 - https://github.com/appcelerator/alloy/blob/624da7094296bdabd5b9e53201948d6f3dac782d/Alloy/commands/compile/index.js#L584 Maybe at the lines mentioned second we can prefix either alloy/controllers or widgetDir?

	template.parentController = (cCode.parentControllerName !== '') ?
		(cCode.parentControllerName : "'BaseController'";