WIP: Consider onConfigurationChanged.

[Rake-Kharton]

Purpose

For handling orientation changes.
Before this fix, each of tabs has too small size when the orientaion is changed.

Reproduction steps

1. Handle the configuration change yourself

<activity android:name=".ThreeTabsActivity"
            android:configChanges="orientation|screenSize"/>

2. Start sample app with portrait screen orientation and change to landscape

Images

	Portrait	Landscape
Before
After	Same to portrait orientation's

[coveralls]

Coverage decreased (-0.2%) to 63.101% when pulling 65c1ec0 on Rake-Kharton:development into e09852b on roughike:development.

[Rake-Kharton]

This PR commits to development branch now, so I change base branch to master.

[Rake-Kharton]

I fixed base branch and send new PR. #788