Fix issue-stopper when adding a duplicate in a WS

http://sentry.bikalabs.com/bikalims/bikalims/group/619/
1399286388.830.202492715254 http://demo.bikalabs.com/worksheets/WS14-028/listing_string_entry
Traceback (innermost last):
  Module ZPublisher.Publish, line 138, in publish
  Module ZPublisher.mapply, line 77, in mapply
  Module ZPublisher.Publish, line 48, in call_object
  Module bika.lims.browser.calcs, line 358, in __call__
  Module bika.lims.browser.calcs, line 317, in calculate
  Module bika.lims.browser.duplicateanalysis, line 43, in __call__
TypeError: float() argument must be a string or a number
Correctly translate header in accreditation page
Remove reference to missing Priority index
Contact is not strictly required on an AR

Loosen the code and defend against missing values
bika_listing: Guard against list values in request
References #931 - reference analysis has no 'part'

@xispa - this is why I think Duplicate/Reference analysis should not
derive from Analysis
Fix #1222 Typo IMM. Small
Merge branch 'develop' of https://github.com/bikalabs/Bika-LIMS into develop
Fix exception - batch is not required field of AR
Fix i18n error

sentry.bikalabs.com/bikalims/bikalims/group/617/
Protective request handling

sentry.bikalabs.com/bikalims/bikalims/group/611/
Fix #1220 IMM. De-activated instruments should not set off Alerts?
Add arimport icon

closes #1231
Reverse created date order for batch folder list

closes #1225
Fix #1223 IMM. Default calculation not showing in AS
Merge branch 'develop' of github.com:bikalabs/Bika-LIMS into develop
Merge branch 'develop' into alspec-int
Cleanup

Demote runtimeerror to warning

WidgetVisibility checks are done at the point where the adapter is
used, not in the adapter itself.  This means that subclassed adapters
don't need to worry about this stuff.

review_states modified centrally in bika_listing.  This means that
subclassed bika_listing/folderitems does not need to worry about this.