ENH: slicer.util.findChildren: Change behavior to an "and" filter

As discussed in [1], this commit changes the behavior so that ALL
parameters (name, text, title and className) are considered when checking
a descendant widget. Prior to this change, the widget was considered
"matched" as soon as the FIRST non-False parameter was matching.

[1] http://slicer-devel.65872.n3.nabble.com/Changing-the-behavior-of-slicer-util-findChildren-td4036266.html

Co-authored-by: Jean-Christophe Fillion-Robin <jchris.fillionr@kitware.com>

From: jonieva <jorgeonieva@gmail.com>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@24957 3bd1e089-480b-0410-8dfb-8563597acbee