private int getNewSourcesCount() {
		return newSources.size();
	}
Look for new sources, metadata, manifest file.  This will find files that need to be 
compiled and files that need to be removed.

<p>If files had errors last time, haven't changed, and no new requirements are available, 
remove them.

@param writer for reporting status to user
@throws IOException while accessing manifest file
@throws OSGiException while parsing imports
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/osgi/GhidraSourceBundle.java