Fix error in baae2a, wrong version of MAIN.dfm

When I merged 3.4.6 into my master, I mistakenly kept
my version of MAIN.dfm instead of keeping the new (good)
version.  (I keep forgetting that when git grumbles about
the file being binary, it is talking about the common
ancestor, not necessarily the file being merged.)
Fix issues with photo and voltage stimulus.

Photostimulus shutter would not close at end of recording, and voltage
stimulus protocols would not start on some rigs at start of recording.
Small changes to RecADCOnly.pas were sufficient to address these.
Fix bug in stimulus_issues which erroneously caused photo stimulus start.

The change made in stimulus_issues to address stimulus protocols not
starting on some rigs was found to erroneously toggle the photostimulus
protocol as well.  This change makes sure only the voltage stimulus is
toggled.
Merge pull request #4 from darrincedwards/stimulus_issues

Fix issues with photo and voltage stimulus.