Qt5

Hello to all the community!

I've (pre-)ported qBittorrent on Qt5.
I managed to get rid of compilation errors on Windows/Linux and build working binary on Linux (I'm using Linux Mint Olivia). I tried to leave the source tree compatible with Qt4...
I'm looking for associates to complete the work and testing on different platforms.
I propose to add a new branch 'qt5' in the main qBittorrent repository.

Thanks!