Patient size csv import too rigid

[Ed McDonagh]

Currently hard-coded to expect three columns headed 'PACS_SPS_ID' for the accession number, 'HEIGHT' and 'WEIGHT'.

Need to be able to pass column titles, and to choose Study Instance UID as an alternative to Accession Number.

[Ed McDonagh]

Added proper arguments processing and capability to use study instance uid rather than accession number. Needs testing. Refs #30.

→ <<cset 3f921eae3c1a>>

[Ed McDonagh]

Tested, further modifications to make both height and weight mandatory and to change the path modification routine. Propose that this is promoted into the scripts folder. Fixes #30.

→ <<cset 6e0f43c96491>>