[issue #23] fix clear patient capture data on edit

The data is now correctly cleared. This also affects the creation of new
patients where now the initial timestamp is set to null. However, to
ensure that every time entered is relative to the time of the incident
all timestamps are corrected now using the incident time as a reference.
Merge branch 'bug/23-clear-patient-capture-data-on-edit' into dev
[issue #24] additional reference time
Merge branch 'feature/24-additional-reference-time' into dev
[issue #25] proper exercise name update
Merge branch 'bug/25-exercise-name-update-on-edit' into dev
remove save debug code
minor dialog text correction