gui: add DropDownWidget widget.

See merge request !7

Automated commit for CI Docker changes

See merge request !6

Try to fix clearing of a dataset

Closes #12

See merge request !5

close #12

This cover the case of process beeing a stack

Implementation can be optional.

add an option to cancel processing

See merge request !3

# Conflicts:
#	processview/gui/processmanager.py

# This is the 1st commit message:

add an option to cancel processing

# Conflicts:
#	processview/version.py

# The commit message #2 will be skipped:

# fix 11cfcc80

# Conflicts:
#	processview/version.py

Add dataset clean up

Closes #9

See merge request !4

CI: update doc creation

See merge request !2

add sorting for dataset

Closes #8

See merge request !1