Bug 6718 Error ticks on non-Java resources
This is a VAME request. They would like to show error ticks on manifest files.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/viewsupport/ProblemMarkerManager.java
private class PkgFragmentRootErrorVisitor implements IResourceDeltaVisitor {
			
			private IPath fRoot;
			private boolean fInsideRoot;
			
			public PkgFragmentRootErrorVisitor() {
			}
			
			public void init(IPath rootPath) {
				fRoot= rootPath;
				fInsideRoot= false;
			}
			
			public boolean visit(IResourceDelta delta) throws CoreException {
				IPath path= delta.getFullPath();
				
				if (!fInsideRoot) {
					if (fRoot.equals(path)) {
						fInsideRoot= true;
						return true;
					}
					return (path.isPrefixOf(fRoot));
				}
				checkInvalidate(delta, path);
				return true;
			}
		}