[TIMOB-19696] Use one term instead ActionBar, TitleBar and NavBar

We're using 3 different terms for the same thing: * Action Bar: [guide](http://docs.appcelerator.com/platform/latest/#!/guide/Android_Action_Bar), [api](http://docs.appcelerator.com/platform/latest/#!/api/Titanium.Android.ActionBar) * TitleBar: [guide](http://docs.appcelerator.com/platform/latest/#!/guide/Android_Action_Bar-section-36735509_AndroidActionBar-HidingtheActionBar), [titanium themes](https://github.com/appcelerator/titanium_mobile/search?utf8=✓&q=notitlebar), [android themes](http://developer.android.com/reference/android/R.style.html#Theme_NoTitleBar) * NavBar: [tiapp.xml](http://docs.appcelerator.com/platform/latest/#!/guide/tiapp.xml_and_timodule.xml_Reference-section-29004921_tiapp.xmlandtimodule.xmlReference-navbar-hidden) It is Android that already makes it confusing by using both ActionBar and TitleBar of course, so I'm not sure how/if we can improve this. Just leaving it here if we think of a good way.