change should not be complex dtype, which would happen if u=complex. Fixed this by not specifying dtype

# Conflicts:
#	proxtoolbox/Utilities/OrbitalTomog/__init__.py
#	proxtoolbox/Utilities/OrbitalTomog/array_tools.py

support for a tqdm progress bar. Simply pass the correct function through the config dictionary. (i.e. tqdm_notebook if using jupyter notebook or tqdm if working through the console.

bugfix for RGB plots

and added pad_to_square from my_tools