More simple drivers

[DanielAndreasen]

The main functions in all the drivers are a bit complicated to read. We should hide the complicated parts away in functions to increase readability, and for easier debugging in the future.

[DanielAndreasen]

This has been done for EWdriver.py with commit 91af0b9. A more complete approach is to make a class based solution, but for now this is sufficient. I suggest we do this with the other drivers too, which are stable. At the moment this is the driver for ARES and abundance. Any takers? Ping: @gdcteixeira @MariaTsantaki.

Remember more lines, isn't necessarily bad (which is the case here). Mane of the extra lines are for documentation each small function. The readability of the single driver is much easier to read now, even without comments.