Add FlexMeasures plugins, USEF protocol, and Cariflex simulator

- flexmeasures-entsoe: ENTSO-E data plugin
- flexmeasures-weather: Weather data plugin
- USEF Flex Trading Protocol PDF (2.4MB)
- Cariflex simulator (publishes to Redis)
- Dashboard Grafana updated with correct InfluxDB queries
- All tools extracted in /tools/

tools/flexmeasures-entsoe/requirements/Readme.md

@@ -0,0 +1,23 @@
+# Requirements
+
+All FlexMeasures requirements are specified in this directory.
+We separate by use case:
+
+- app: All requirements for running the FlexMeasures platform
+- test: Additional requirements used for running automated tests 
+- dev: Additional requirements used for developers (this includes testing)
+
+Also note the following distinction:
+
+
+## .in files
+
+Here, we describe the requirements. We give the name of a requirement or even a range (e.g. `>=1.0.`).
+
+## .txt files
+
+These files are not to be edited by hand. They are created by `pip-compile` (or `make freeze-deps`).
+
+They are usually not needed, only for development environments. When distributing FlexMeasures with pinned dependency versions and this plugin, only the extra app dependencies (see .in file) need extra care beyond the .txt files.
+
+Each requirement is pinned to a specific version in these files. The great benefit is reproducibility across environments (local dev as well as staging or production).