Add setting option to lock screen to portrait or landscape while app is open

[Google Code Exporter]

What steps will reproduce the problem?
1. Have screen rotation enabled.
2. Open premotedroid app
3. tilt the screen

What is the expected output? What do you see instead?
Since I control the screen while lying on sofa or bed the screen orientation 
changes to landscape. I want to lock this app to portrait. Most other apps(like 
pdf reader etc) have this option. And I do not want to turn off screen rotation 
since I want to use it for browsing and youtube etc.

Original issue reported on code.google.com by [e-mail] on 11 Jun 2013 at 8:11