fix race condition likely causing null ptr exception when registering a listener.
Fixes #218
fix in add source dialogs: initialize proeprty change support after object has been fully initialized
Merge branch 'master' of https://github.com/sleuthkit/autopsy

Conflicts:
	Core/src/org/sleuthkit/autopsy/casemodule/ImageFilePanel.java
better way to ensure pcs has been initialized
fix pcs initialization issues for good (linux) by lazy instantiating pcs before it's used