gril: Add functions for devinfo re-factor

Functions for parsing replies needed by rilmodem devinfo module.
rilmodem: Re-factor devinfo

grilreply functions are used now for parsing parcels
unit: devinfo replies parsing tests
Merge pull request #35 from alfonsosanchezbeato/devinfo-refactoring

Devinfo refactoring
unit: Add tests for gprs/netreg re-factoring

Also cleaned up formatting of parcel hex data
which inadvertently included tabs as whitespace
between bytes instead of spaces for some messages.