Rilmodem test

Initial set of rilmodem specific test scripts.  Some are specifically designed to run in the emulator ( test-hangup-all ), as they required emulator console commands, whereas others are designed to be run on live hardware as well ( test-modem-offline and test-sim-online ).

Note, test-sim-online offers a number of command-line arguments which allow it to match against pre defined values.  For instance, specifying --emulator, will cause it to check property values against hard-coded values used in the emulator.   It also allows you to specify property values for MobileNetworkCode ( --mnc ), MobileCountryCode ( --mcc ), ...