Merged payno requested to merge rework_vds into master Dec 02, 2020

TODO

Insure virtual dataset is correctly recreate and that we can create a new virtual source even if a 'fancy selection' is made on the original dataset (using python slice, list...)
add option "--embed-data". Set to False by default
rework _insert_frame_data to be a class.

Edited Dec 02, 2020 by payno