Fix #276: Use regex to parse config file

[boschmitt]

Description

Slightly more robust solution to parse target config scripts. We must re-address this when we refactor the driver.

[schweitzpgi]

Won't this match config lines that are commented out?

[schweitzpgi]

It could be more robust to have the options passed in as command line arguments or environment variables rather than trying to reparse the configuration file.

[boschmitt]

Won't this match config lines that are commented out?

It will indeed. I can adjust the regex. (Edit: but then someone could come up with modifying this variable in some if statement, or use a +=. Unless we implement something as suggested bellow, there will most likely be loose ends)

It could be more robust to have the options passed in as command line arguments or environment variables rather than trying to reparse the configuration file.

Actually this is what I thought that was happening from the beginning. Since I'm unsure if other parts of the runtime are relying on parsing this file, I went to with trying to fix it by changing overall behavior as little as possible.