Custom actions and categories for BroadcastReceiver

android.broadcast.BroadcastReceiver now accepts
non-standard actions & categories. Detects by checking
the presence of '.' on the name of it
Factored out the Intent name expansion
Simplified via list comprehensions
Oops: was broken if categories[] empty
Merge pull request #189 from alanjds/custom_intent_filters

Custom actions and categories for BroadcastReceiver