Performance work

1. types now keep track of their subtypes, enabling smarters checks
   after reloading: "has anything in my hierarchy been reloaded?"
   instead of "has anything at all been reloaded?"

2. Building on that, caches related to info built during reflective
   calls like 'getDeclaredMethods()' and 'getMethods()' is cleared
   from types (and subtypes) during reload. The caches will
   subsequently be rebuilt/reused on the next request for that
   info.

3. New guards in ivicheck/etc: 'have things in my
   hierarchy been reloaded?'

testdata-subloader/src/main/java/subassociatedtypes/CB.java

@@ -0,0 +1,7 @@
+package subassociatedtypes;
+
+import associatedtypes.CM;
+
+public class CB extends CM implements IB,IB2 {
+
+}

testdata-subloader/src/main/java/subassociatedtypes/IB.java

@@ -0,0 +1,5 @@
+package subassociatedtypes;
+
+public interface IB {
+
+}

testdata-subloader/src/main/java/subassociatedtypes/IB2.java

@@ -0,0 +1,5 @@
+package subassociatedtypes;
+
+public interface IB2 {
+
+}