AVFMediaPlayerSession::setMedia() fails if QUrl contains spaces

note this bug report comes with a free SOLUTION (see step 6)

repro steps:

1. on mac, open example project "Video Widget"
2. in AVFMediaPlayerSession, put a breakpoint on line 543 (inside static void setURL() ), if you can't, then in videoplayer.cpp, put breakpoint on line 124 (m_mediaPlayer->setMedia(url); )
3. run and open a file that has a space in its path
4. hit the breakpoint.  if you could not break into AVFMPS, step in until you get to the static setURL() function
5. note that NSURL *nsurl = [NSURL URLWithString:urlString];  is NULL since the url string is NOT percent escaped, therefore this entire thing will fail
6. in AVFMediaPlayerSession, line 595, add "QUrl::FullyEncoded" as a parameter to the "toString()" call
7. run and open a file that has a space in its path
8. now it works???
9. ship it