ofxVideoRecorder seems to fail when the path to app (and ffmpeg) has spaces in it

[ofZach]

I noticed a couple of issues -- it's all a little hazy but some notes if helpful

a) open(...) used to get the file handle for the pipes, seems unhappy when the path has spaces b) the commands for ffmpeg seem unhappy when there is spaces in the path to ffmpeg

about (a) I am not 100% certain but I think it's an issue. the solution for me for (a) was to use a relative path without spaces -- since I'm doing something kind of funky and having ffmpeg inside the app bundle and for (b) the solution was to modify how the command is put together and wrap the path to ffmpeg in some quotes.

I'll investigate this some more before a PR but in case it's helpful, just writing some notes here.