constrain default order on models #423

This attempts to partially resolve issues surrounding default ordering
on models. Order has been removed from associations where the order
has already been specified on the target model. In all other cases the
ordering has been scoped to the table. This should not modify the
order specified to any queries.

This allows cases, etc. to perform joins without
explicitly removing order constraints. Possible performance overheads
associated with unnecessary sorting are still an issue. Also, model
class names have been hardcoded to scope associations. I am not sure
how to get around this.

The goal is to allow cases to use mainline surveyor releases.
display times in rails configured timezone #435

testbed now has a (non-utc) timezone by default so that the model data
is different from the database and this functionality is covered by
rspec, cucumber.

fixes bug in datetime, where afternoon times are recording as
morning. This was already implemented in cases, see
https://code.bioinformatics.northwestern.edu/issues/issues/show/3415
bugfix, make roman time optional #435
Pull new render methods into show action:
- Group text translations (#420)
- Answer help text (#373)
- Show labels
Closes #438, closes #442. Thanks @alanjcfs.
Merge branch '423_constrain_default_ordering'.

* 423_constrain_default_ordering:
  constrain default order on models #423
move testbed timezone to Rakefile #435

Set the testbed timezone in the Rakefile so as not to unnecessarily
interfere with generators used for production.
Merge branch '435_times_in_rails_timezone'. Closes #435.

* 435_times_in_rails_timezone:
  move testbed timezone to Rakefile #435
  bugfix, make roman time optional #435
  display times in rails configured timezone #435
recording changes
releasing 1.4.0
prep for ongoing development
Gem prerelease qualifiers are usually separated with a dot.

See: http://guides.rubygems.org/patterns/#prerelease-gems .
Allow date_value= and time_value= to handle nils.

Also adds specs for the existing (not null) behavior.
Log change for #450.
Merge pull request #450 from NUBIC/fix_response_datetime_nils

Correct nil handling in date_value= and time_value=