Exporting studies can fall over if cumulative RDSRs are being imported

[Ed McDonagh]

Attempt to export 'today' with 0.8.0b1 from a modality that produces a new (cumulative) RDSR for each event.

Export stopped with DoesNotExist error on

File "remapp/exports/ct_export.py", line 154, in ctxlsx
    for s in exams.ctradiationdose_set.get().ctirradiationeventdata_set.order_by('id'):


raised unexpected: DoesNotExist('CtRadiationDose matching query does not exist.')

Second attempt at exporting the same query succeeded without error.

Suspect the first attempt was exporting a particular study when it was deleted to be replaced by a later RSDR with more events in.

[Ed McDonagh]

Wrapping CT export in try/except for ref #589

→ <<cset ca3fbda5c0c3>>

[Ed McDonagh]

Set error message to be printed in all_data sheet as well as error log. Also fixing error of max_events bing zero that occurred whilst testing ref #589

→ <<cset 98d9242323ff>>

[Ed McDonagh]

Factoring out the zero studies fix into a shared function. Sort of refs #589

→ <<cset 17c13caba7f7>>

[Ed McDonagh]

Sorting ref #589 for DX plus zero studies fix.

→ <<cset 58fded9b6fa7>>

[Ed McDonagh]

Replicated DX CSV fix for ref #589 in CT CSV exports. Minor change to DX export

→ <<cset 097af1c5ef5d>>

[Ed McDonagh]

Applying fixes to mg csv nhsbsp export refs #589.

→ <<cset 92f8b820ae95>>

[Ed McDonagh]

Applying fixes to mg csv and xlsx export refs #589.

→ <<cset e1f7eb0e1934>>

[Ed McDonagh]

Applying fixes to RF csv and xlsx export refs #589.

→ <<cset 8c30ebd1104d>>

[Ed McDonagh]

Adding ref #589 to changes.

→ <<cset 059fefa34cdb>>

[Ed McDonagh]

Merged in issu589exportAndMultiRDSRImportClash (pull request #158)

Fixes #589

→ <<cset fde730a6a302>>