RDSR with Acquisition Protocol CodeMeaning but no TextValue crashes on import

[Ed McDonagh]

Attempts to pass value to safe_strings, (which should be unnecessary now), and causes AttributeError.

[Ed McDonagh]

Small try except to to deal with ref #612. Would like to also drop safe_strings but need to see if it is tested.

→ <<cset 66d42bb0cf20>>

[Ed McDonagh]

Added ref #612 to changes, also in this PR

→ <<cset 7849d54b12fa>>

[Ed McDonagh]

Merged in issue580againnewimports (pull request #177)

Issue 613 fix new dual imports after dual designation

Fixes #612, #613

→ <<cset 371d6bb0153b>>