Bug 139986 [CommonNavigator] Convert catch(Error/Throwable) to SafeRunner
In several places the CN framework uses catch(Error/Throwable) to ensure that code does not bring the framework down. Change these to use SafeRunner.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/navigator/CommonDropAdapter.java
for (int i = 0; i < assistants.length; i++) {
				if (Policy.DEBUG_DND) { 
					System.out
							.println("CommonDropAdapter.validateDrop checking assistant: \""+assistants[i]); 
				}					
				try { 
					assistants[i].setCurrentEvent(getCurrentEvent());
					valid = assistants[i].validateDrop(target,
							theDropOperation, theTransferData); 
				} catch (Throwable t) {
					NavigatorPlugin.logError(0, t.getMessage(), t);
				}
				if (valid != null && valid.isOK()) {
					result = true;
					if (Policy.DEBUG_DND) { 
						System.out
								.println("CommonDropAdapter.validateDrop VALID"); 
					}					
					break;
				}
				if (Policy.DEBUG_DND) { 
					System.out
							.println("CommonDropAdapter.validateDrop NOT valid: " + (valid != null ? (valid.getSeverity() + ": " + valid.getMessage()) : ""));  
				}					
			}
		}
		if (Policy.DEBUG_DND) {
			System.out
					.println("CommonDropAdapter.validateDrop (returning " + (valid != null ? valid.getSeverity() + ": " + valid.getMessage() : "" + result) + ")"); 
		}