refinements to the navigation drawer

 * Fix a bunch of bugs in the navigation drawer and make it look much better. 
 * Add button now available in action bar from StudyOptions, and in same location throughout the app
 * Added the help menu items to drawer following the same style as Google apps like gmail
 * Help link now launches FAQ directly without intermediary dialog
 * Send feedback now opens the main help page (could perhaps send email to mailing list instead?)
 * About dialog now accessed via Preferences as in Gmail, Google Play, etc
 * Open ND when app is first opened until user voluntarily opens the drawer, as per [Android guidelines](https://developer.android.com/design/patterns/navigation-drawer.html#Interaction)
 * Make custom fonts dialog generate only when opening fonts submenu to avoid UI delay when choosing settings from the ND


![untitled](https://cloud.githubusercontent.com/assets/2818274/3208564/09d6584e-ee3c-11e3-83ab-794c5e58c0fd.png)