Allow to split treatment and gain in readibility of the code.

Manage id15 data

See merge request !28

[converter] refactoring: split the edf and the hdf5 convert. Add classes for each possible acquisition type for hdf5

# Conflicts:
#	nxtomomill/converter.py
#	nxtomomill/settings.py

# Conflicts:
#	nxtomomill/converter.py
#	nxtomomill/settings.py

[covnerter][plugins] add management of output dataset write to avoid doing operation at nxtomomill side

# Conflicts:
#	nxtomomill/converter.py

# Conflicts:
#	nxtomomill/settings.py

# Conflicts:
#	nxtomomill/converter.py

# Conflicts:
#	nxtomomill/converter.py
#	nxtomomill/settings.py

# Conflicts:
#	nxtomomill/converter.py

# Conflicts:
#	nxtomomill/app/tomoh52nx.py
#	nxtomomill/converter.py
#	nxtomomill/settings.py

# Conflicts:
#	nxtomomill/converter.py