Added initial partial rewrite of termperature bus and device support
via DallasTemperature and Onewire libraries.
Added skeleton of GPRSDevice (not used yet)
Changed Globals to a class and added per feature flags to allow fine grain
enable and disable ment of features at runtime.
All basic hardware is working and associated Alarm logic.
Communication is still left to be done.

The following is a summary of the supported hardware and attendant function:

1) Thermometers:  Support one indoor and outdoor thermometers that have indepenent
                  alarm thresholds (one wire bus on pin 2)
2) Motion Detector:  A single PIR sensor that looks for motion and triggers an alarm
                     when a threshold is reached (defaults to 3 but can be set)
                     pin 3
3) Remote Power Control: used to control an RF remote power module
                         (pin 4:on, pin 5:off).  If configured will use
                         the remote power detector to confirm that its state
                         matches to true state of the remote power module.
4) 6 Reed Switches: Front Door (pin 6), Sliding Door (pin 10), Entry Window (pin 11),
                    Bathroom Window (pin 12), Kitchen Window (A0), LivingRoom Window
                    (A1).  Independent switches to sense the state of a given
                    window and triggers on alarm if open.
5) Speaker : Small Piezo Electric speaker on pin 13
6) Cabin Power Detector : Pin A2, monitors state of +5 volt external supply.
                          Loss of power triggers Alarm
7) Remote Power Detector : Pin A3, monitors state of +6 volt supply that is connected
                           to the remote power module.  Does not itself trigger any
                           alarms.  However, the remotePower code uses it to trigger
                           an alarm if an inconsistent state is found.
8) Red and Yellow Leds:  Pins A4 and A5, Used to give some external feed back on state:  Led support flashing at different rates.  Currently Yellow is used by motion
code to indicate a motion event (on during motion event) and the red is used to show
the state of the Alarm (armed and triggered).

Synthetic and additonal function:
9) Each device supports and enable/disable logic that can be used to turn on or off
devices independently
9) Alarm is the synthetic device that uses the state of all the device specific alarms to cause global alarm behavior to be enacted.  It aupports arm and disarm logic

I am sure there is more I should be saying but that's roughly the major features.

Bad me... This commit encompasses a lot of changes (some
transitory debug code has been lost but should be easy
enough to replicate if needed)
First more or less complete version.  All subsystems including
cell communications are working.

Modifed Software Serial to customize it for modem communication.