Use KDEInstallDirs from ECM rather than a self-cooked fork of the kde4 stuff.

This fixes automatically installing into lib64 rather than lib.
Last commit made these vars relative; set absolute paths here again.
Include moc generated files.

If we don't include moc generated files, we won't be able to
link the libraries to any program because of unresolved symbols.
Manually specify the needed modules.

Fix build by specifying all the Qt 5 modules and include QDBusMessage
from core/polkitqt1-authority.h.
Full Qt 5 port.
Fix Build error with Qt 5

Use QtWidgets headers instead of QtGui.
Check for Qt5DBus and Qt5Xml.

polkit-qt-gui-1 needs them.
Merge branch 'hawaii' of github.com:hawaii-desktop/polkit-qt-1 into hawaii