Added support for transparent holo themes which were missing

The only available translucent theme on Android (and therefore in ActionbarSherlock) is :

    @android:style/Theme.Translucent.NoTitleBar

The problem with this theme is that any component added to an Activity which has this theme, will be styled with a Gingerbread UI.

This commit adds 3 themes to ActionbarSherlock :

    Theme.Sherlock.Translucent
    Theme.Sherlock.Translucent.NoTitleBar
    Theme.Sherlock.Translucent.NoTitleBar.Fullscreen