Add missing license headers

Examples get the BSD license header.

Change-Id: I4802cc00815c69e2f113aa8973d61203357212e3
Reviewed-on: http://codereview.qt-project.org/4849


Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Rohan McGovern <rohan.mcgovern@nokia.com>