Increased compatibility to API > 9

Hi,

I changed the tab bar such that it is also compatible with api 10 and higher.

Kind regards,
Pieter
Use public static final value: [Build.VERSION_CODES.HONEYCOMB_MR2](http://developer.android.com/reference/android/os/Build.VERSION_CODES.html#HONEYCOMB_MR2)

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR2)