From date (only) in QR acts as single date

[Ed McDonagh]

In working through how to implement issue ref #554, I have realised that in commit 242fe94 create_dcm_date_range changed so that if the date_until is not set, instead of creating a date range of date_from to the current date, it returns a single date.

[Ed McDonagh]

Adding test showing make_dcm_date_range is wrong for setting start date only. Refs #713

→ <<cset d91c01b6229f>>

[Ed McDonagh]

Added date_single bool to make_dcm_date_range. Updated tests. Need to update usage from qrscu. Refs #713.

→ <<cset 13e4de814866>>

[Ed McDonagh]

Merged in issue554QRtime (pull request #273)

Fixes #554 QR with time and fixes #713 start date only in make_dcm_date_range wrong

→ <<cset 4efd50e87920>>