Merge pull request #28 from alfonsosanchezbeato/voicecall-refactor

Voicecall refactor
Merge pull request #30 from alfonsosanchezbeato/fix-leaks

rilmodem: Fix for memory leaks
rilmodem: Parse reply to check for file not found
gril: Fix ril_msg invalid event_data bug

Wrong event data instead of nothing was being passed to upper layers
when the parcel had no event data (LP #1254219).