Bug#922813: Update pianobooster (qt4->qt5)

[Alexey Loginov]

Package: pianobooster
Version: pianobooster_0.6.7~svn156

There is pianobooster-0.7.0 with qt5 support:
https://github.com/captnfab/PianoBooster
and debian branch: https://github.com/captnfab/PianoBooster/tree/debian