The .qdocconf file for Qt Print Support includes examples/widgets in
its exampledirs, presumably because a few examples there have printing
support. The documentation for these examples is not accessible from
Print Support index/module pages, and qdoc prints a lot of warnings
for them (missing images).

There's only few dependencies to examples in Print Support docs.
These are resolved by copying a code snippet to correct place,
and removing \sa links from QAbstractPrintDialog.

Task-number: QTBUG-31137
Change-Id: Iac20d151f93ac16449241c6ee85979781b26e607
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>