Hardware Version 4.1 ready for merging and ordering

[timburke]

Update Controller Hardware to Version 4.1

This PR contains the latest hardware design files for the MoMo controller and gsm_module. The controller is updated to fix the RF interference issue as well as to support BTLE and fix the solar panel charging issue. This is the final hardware for the 100 unit order.

The gsm_module is updated just to remove the ground plane from under the antenna connection.

closes #137 closes #102

Specific updates follow

Update controller board to rev 4.0.

• New version contains BTLE via Microchip RN4020 module
• Current monitor for solar and external charging current
• Move 2.8V linear regulator and add RF filtering caps to fix RF interference problems on GSM transmission.

Update controller board to version 4.1

• Replace Li-ion battery charger IC with constant current regulator to allow for solar panel charging
• Add solar panel current measurement with 1 ohm shunt and differential ADC lines
• Fix battery charging and simplify reset circuit.
• Remove MOSFET from battery- to minimize R on GSM power supply
• Add constant current charger for charging from external source
• Update parts to compatible versions with lower cost D1-3, Q2,4
• Update part sizing document.
• Update HW Reset components for increased reliability based on SPICE
• larger RC network on discharge FET.
• increased required assert time to 120 ms.
• reset pulse length: ~100 ms @ 25C
• Rename controller board from combined_controller
• Update controller project file.
• Remove autorouter file.
• Update labeling on schematic Add spice models for controller battery charging and hw reset Update cosmetic changes to controller, remove wrong gnd plane in gsm_module Remove ground plane from under BTLE module for antenna performance Update gnd plane removal for larger antenna clearance Add final trace connecting battery to 2.8V regulator. Renamed part to controller. Update board with final wiring and add additional io line to btle Update V+ pour.