Bug 24212 [Tasks view] Support read-only tasks in Task list
JDT has now support for generating tasks from source, e.g. //TODO will add a task and show it in the task list. Such tasks can only be edited and changed in the source code. For this reason we would like to have support in the task list for such non-modifiable tasks. For example, we could add a marker attribute "read-only" and if this attribute is set then menu actions to delete or change the task will be disabled.
bundles/org.eclipse.ui.views/src/org/eclipse/ui/views/tasklist/MarkerUtil.java
int result = 0;
	while (i < len) {
		int digit = Character.digit(value.charAt(i++), 10);
		if (digit < 0) {
			return result;
		}
		result = result * 10 + digit;
	}
	if (negative) {
		result = -result;
	}
	return result;
}
/**
 * Returns the priority of the given marker.  Default is PRIORITY_NORMAL.
 */
public static int getPriority(IMarker marker) {
	return marker.getAttribute(IMarker.PRIORITY, IMarker.PRIORITY_NORMAL);
}
/**
 * Returns an image that should visually represent marker's priority
 * in the tasklist.
 */
public static Image getPriorityImage(IMarker marker) {
	switch (getPriority(marker)) {
		case IMarker.PRIORITY_HIGH:
			return getImage("hprio");
		case IMarker.PRIORITY_NORMAL:
			return null;  
		case IMarker.PRIORITY_LOW: