bf/trafo_std.c: Fix a UI crash if a trigger file cannot be opened, in which case
the end-of-trigger-list marker may not be written correctly: Use the growing_buf current_s
as well.
python updates: Support dim_simulate and null_source;
Added avg_q/numpy_Script.py for a Script interface approach to read data
from avg_q to numpy and a numpy_Epochsource to write numpy data to avg_q;
Moved mapplot and traceplot from avg_q to numpy_Script.