fix junit tests
GUI: log detected distro/os
PCMK: don't use names from the RA, but the filename
GUI: add some debug info
GUI: show error if gui helper doesn't work in cluster wizard

fixes also npe later on:
java.lang.NullPointerException
null
lcmc.gui.dialog.cluster.CoroConfig.getInputPane(CoroConfig.java:955)
lcmc.gui.dialog.ConfigDialog.body(ConfigDialog.java:250)
lcmc.gui.dialog.ConfigDialog.showDialog(ConfigDialog.java:478)
lcmc.AddClusterDialog.showDialogs(AddClusterDialog.java:56)
lcmc.gui.EmptyViewPanel$2$1.run(EmptyViewPanel.java:145)
fix appError without stack trace
GUI: better error handling in corosync/heartbeat config wizard