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

Need to add click listeners to make it useful, but hopefully this provides a way to manage the various cases of how we render action bars.

Usage:

DynamicActionBar bar = new DynamicActionBar(RequestMapActivity.this, DynamicActionBar.ActionBarColor.DARK_BLUE);
bar.setText("Here we go");
bar.showLeftArrow(false);