Switch to Action Bar

Signed-off-by: Jui-You Tang <david.tang@tangentsoftworks.com>
Remove category code

Signed-off-by: Jui-You Tang <david.tang@tangentsoftworks.com>
Add 薪傳學院 tab

Signed-off-by: Jui-You Tang <david.tang@tangentsoftworks.com>
Change action bar height

Signed-off-by: Jui-You Tang <david.tang@tangentsoftworks.com>
Style the action bar

Signed-off-by: Jui-You Tang <david.tang@tangentsoftworks.com>
Finish adding main tabs

Signed-off-by: Jui-You Tang <david.tang@tangentsoftworks.com>
Adjusted preferred courses layout

Signed-off-by: Jui-You Tang <david.tang@tangentsoftworks.com>
Move JSON loading to MainActionBarActivity and implements callback

Signed-off-by: Jui-You Tang <david.tang@tangentsoftworks.com>
Add a skeleton category tab

Signed-off-by: Jui-You Tang <david.tang@tangentsoftworks.com>