With this change the window should appear immediately. It will still be
unusable and frozen until all capababilities are queried, but should at
least give the user some indication that something is happening.
The QProcess::start() method is replaced with a new one that requires
executable path and arguments passed separately.
Each argument must be now passed individualy using QStringList and
have their spaces escaped automatically and passing argument
list as a single string would no longer work. This is now handled by
splitting the argument string on spaces.
The executable path can no longer contain quotes as spaces are escaped
by QT automatically now.
