quick fixes, showcase

some fixes made after the showcase,

- middle app is now also an FBO and supports syphon
- various bugfixes
- ignore incoming osc button
- intentie_interpretatie no longer needs a viewport (changed content
ratio)
- c button toggles hiding the cursor (in case you need it for the
middle app)

- zoetroop quick fix, he didn't like seeng counter-clockwise rotations
(now still some funky stuff but at least it rotates again under zero)
- plaats_origine quick fix, strange modulo thing going on where it
tells osc that there could be as many as 48 backgrounds
- interview bezoekers no longer plays every movie on each app, only the
ones that are relevant
- osc timestamp only gets send if movie is playing
-