Since we have no many RaspberryPi based control systems running at our lab with midas, I want to 
streamline the midas installation, such that a non-expert can install it on these devices. 

First, midas has to be cloned under "midas" in the user's home directory with

git clone https://bitbucket.org/tmidas/midas.git --recurse-submodules

For simplicity, this puts midas right into /home/<user>/midas, and not into any "packages" subdirectory 
which I believe is not necessary.

Then I wrote a setup script midas/midas_setup.sh which does the following:

- Add midas environment variables to .bashrc / .zschenv depending on the shell being used

- Compile and install midas to midas/bin

- Load an initial ODB which allows insecure http access to port 8081

- Install mhttpd as a system service and start it via systemctl

Since I'm not a linux system expert, the current file might be a bit clumsy. I know that automatic shell 
detection can be made much more elaborate, but I wanted a script which can easy be understood even by 
non-experts and adapted slightly if needed.

If you know about shell scripts and linux administration, please have a quick look at the attached script 
and give me any feedback.

Stefan