Reverts r5372 and fixes former type juggling regression.

selectInput()'s $onchange argument used to accept boolean
like values, e.g. 1, '1'.

Comparing to boolean first silently broke the check due to
introduced type juggling, and strict check further
changed the behavior.

In this scenario the type strict check doesn't do much
more than limits value options. The attribute itself has no
reason to be type strict. You will be never wanting to
inject '1' to the HTML tag's attribute list.

As such, change the check to funky strict comparing in
string presentation. This prevents numeric parsing issues,
but allows boolean like values be used instead of a real
boolean.

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5382 2fea6a4d-a838-0410-917b-93a53c48e9d2