ClassUtils: trap more class loading errors

No class loading error should crash the thread, ever.

Ops just switched to Java 8. Unfortunately, this change
crashed the context startup in the following way:

java.lang.UnsupportedClassVersionError: net/imagej/ops/DefaultNamespaceService : Unsupported major.minor version 52.0
	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
	at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
	at org.scijava.util.ClassUtils.loadClass(ClassUtils.java:164)
	at org.scijava.plugin.PluginInfo.loadClass(PluginInfo.java:283)
	at org.scijava.plugin.PluginInfo.getIdentifier(PluginInfo.java:320)
	at org.scijava.AbstractUIDetails.getTitle(AbstractUIDetails.java:108)
	at org.scijava.AbstractUIDetails.compareTo(AbstractUIDetails.java:237)
	at org.scijava.AbstractUIDetails.compareTo(AbstractUIDetails.java:43)
	at java.util.ComparableTimSort.binarySort(ComparableTimSort.java:232)
	at java.util.ComparableTimSort.sort(ComparableTimSort.java:176)
	at java.util.ComparableTimSort.sort(ComparableTimSort.java:146)
	at java.util.Arrays.sort(Arrays.java:472)
	at java.util.Collections.sort(Collections.java:155)
	at org.scijava.object.SortedObjectIndex.mergeAfterSorting(SortedObjectIndex.java:97)
	at org.scijava.object.SortedObjectIndex.addAll(SortedObjectIndex.java:83)
	at org.scijava.plugin.PluginIndex.discover(PluginIndex.java:108)
	at org.scijava.Context.<init>(Context.java:261)

Author: ctrueden

src/main/java/org/scijava/util/ClassUtils.java

@@ -163,7 +163,11 @@ public static Class<?> loadClass(final String name,
 					: classLoader;
 			return cl.loadClass(className);
 		}
-		catch (final ClassNotFoundException e) {
+		catch (final Throwable t) {
+			// NB: Do not allow any failure to load the class to crash us.
+			// Not ClassNotFoundException.
+			// Not NoClassDefFoundError.
+			// Not UnsupportedClassVersionError!
 			return null;
 		}
 	}