consider the case that an appoinment is not set to a particular visit. the subsequent functions that replace tags in template support variables with None value #435

Resolve "subject import should allow to set values in custom fields"

Closes #385

See merge request NCER-PD/scheduling-system!307

Merge 1.0.1

See merge request NCER-PD/scheduling-system!316

Resolve "Allow for adding modifying types of subjects"

Closes #371

See merge request NCER-PD/scheduling-system!305

Docker issue

See merge request NCER-PD/scheduling-system!313

Resolve "in Appointments the Workers are not visible"

See merge request NCER-PD/scheduling-system!312

Merge remote-tracking branch 'origin/devel_1.0.x' into 377-in-appointments-the-workers-are-not-visible

Merge branch '381-allow-for-longer-url-in-gunicorn-so-subjects-are-fetched-properly-in-subject-list-view' into 'devel_1.0.x'

Resolve "allow for longer url in gunicorn so subjects are fetched properly in subject list view"

See merge request NCER-PD/scheduling-system!311

Merge branch '383-saving-subject-with-custom-date_field-makes-subject-form-unusable' into 'devel_1.0.x'

Resolve "saving subject with custom date_field makes subject form unusable"

See merge request NCER-PD/scheduling-system!310

Merge remote-tracking branch 'origin/devel_1.0.x' into 381-allow-for-longer-url-in-gunicorn-so-subjects-are-fetched-properly-in-subject-list-view

Merge remote-tracking branch 'origin/devel_1.0.x' into 383-saving-subject-with-custom-date_field-makes-subject-form-unusable

Resolve "admin cannot unfinish visit"

See merge request NCER-PD/scheduling-system!309

Resolve "problem with generating documents"

See merge request NCER-PD/scheduling-system!308