Implement Basic Model Interface (BMI) for SUMMA

[bartnijssen]

Implementation of BMI (Basic Model Interface) will allow for easier coupling of SUMMA to other models. The issue is motivated by a talk by Scott Peckham at the EGU 2016 meeting (http://meetingorganizer.copernicus.org/EGU2016/EGU2016-9508.pdf).

For more information see here:
https://csdms.colorado.edu/wiki/BMI_Description

[bartnijssen]

@arbennett is doing some work on this as part of the eWaterCycle project with Delft Technical University: https://github.com/arbennett/summa/tree/bmi

[andywood]

This may be accruing strategic value -- the NWM is shifting toward a BMI standard and there could be interest in integrating SUMMA as an NWM option. One way to do this may be to create a new BMI-based-driver for summa but it will be important to maintain standalone modes of running (so that the BMI-layer doesn't become an obstruction to a normal use of SUMMA).

[arbennett]

For what it's worth the more complete implementation is here: https://github.com/eWaterCycle/summa/tree/develop

The BMI interface was working, but obviously it's so old at this point that it would need to be reworked. The nice thing about BMI though was it should be pretty easy to get working again, since it's all very high level stuff. Most of the code is in source/driver.