Fix for seeInField for radio, checkbox and select

seeInField/dontSeeInField was not working with radio, checkbox and
select fields.  Cleaned up code a bit, and created tests.
Caused error using 'exact' match with an array

The string concatenation for failure message caused an error if the
passed $field was an array for an exact match.  Added test.
Allow boolean values for checkbox/radio buttons

Allows checking against boolean values for seeInField if the field
is a radio button or checkbox.
Merge pull request #1543 from zbateson/seeInField-fix

Fix for seeInField for radio, checkbox and select