Set minSdkVersion=3 in AndroidManifest.xml because in NumberPicker.java
two methods that were only introduced in API level 3 are called:

android.widget.EditText#setOnEditorActionListener
android.widget.EditText#setRawInputType

With that, the @SuppressWarnings({"UnusedDeclaration"}) annotation on
NumberPicker can be deleted, as it no longer suppresses any warnings
that we don't want to see.

Also set targetSdkVersion=15 (ie. the same as in project.properties) in
the manifest.
Remove unused code (which probably was added because it once was used
for logging, or because it was thought it might be used for logging in
the future).
Merge pull request #13 from roubert/dev

Cleanup: Update manifest, remove suppression of warnings and delete unused code.