The parser now looks for vars with name pause_message and end_message to set these special values. If none are found, fall back on defaults.

The default values for pause_message and end_message are therefore not set in main.py anymore.

config-h.txt was changed to showcase the changes made.
Renamed a method to a more apt name
Added comments for clarity
There is now a separate method to gen an experiment from a line.

Also renamed var type -> step-type in gen_part_array(..) in order not to shadow the built-in type function.
The parser now correctly differenciates multi-step experiments from different experiments (that are separated by at least 1 blank line).
Corrected a bug where a space was always assumed after the variable name in the first part of the line, where it's not in the doc. Now behaves as expected.
Changed the config.txt to showcase all the features of the language created so far. Renamed it to the simpler "config.txt"