Dynamic action bar that allows left/right arrows to hide/show, set text.

Hopefully this provides a way to manage the various cases of how we render action bars.  We have to go with a custom layout, so the default ActionBar stuff just doesn't cut it.   See http://www.androidpatterns.com/uap_pattern/action-bar for more context.

![image](https://f.cloud.github.com/assets/326857/1461483/e2c398a2-44b3-11e3-8db0-b8e6254e9eb4.png)


Usage:

```
		DynamicActionBar bar = new DynamicActionBar(RequestCreateActivity.this, getResources().getColor(R.color.dark_blue));

		bar.setTitle("Here we go");
		bar.setLeftArrowVisibility(View.VISIBLE, new View.OnClickListener() {
			@Override
			public void onClick(View v) {
				Toast.makeText(RequestCreateActivity.this, v.getTag().toString(), Toast.LENGTH_SHORT).show();
			}
		});
```