- Moved all platform-specific code to UBPlatformUtils
- For now, removed support (on Linux) for checking whether onboard is 
running when OpenBoard is started (it wasn't working anyway, but it needs a
cleaner solution for all 3 platforms)

The project didn't compile on Windows.. list of modifications:

- Added essential changes that hadn't been committed / pushed (Qt4->Qt5
changes; other misc. changes by Abdel)
- Temporarily disabled podcasts, as the modules don't compile with Qt5.2/
5.5

Currently, the application compiles on Windows, with MSVC2010 32-bit

Due to QWidget::showFullScreen having side-effects on OSX (setting the
dock and menubar to autohide, making it impossible to then set them as
hidden), the calls to that method were replaced with
UBPlatformUtils::showFullScreen(QWidget *). This function then calls
QWidget::showMaximized() on OSX, or QWidget::showFullScreen() on Linux
and Windows.

It is currently still impossible to switch smoothly between showing or
hiding the dock on OSX; current behaviour is to hide it all the time,
even in desktop mode.

removed redundant OBCocoa files / namespace; moved functions to UBPlatformUtils, which serves the same purpose

Changing the languages of the virtual keyboard crashes the software

fixed issue SANKORE-574 and font manager is now translated depending on the system lanaguage (linux only but other will be fixed soon too) and some script build issues fixed on linux