Fix a bug where ' (apostrophe/single quote) was being escaped with &pos instead of the correct &apos.

Change-Id: I6f0b5b7e7beed2ca7878460d99619f0a016ebed1
diff --git a/src/com/google/doclava/Stubs.java b/src/com/google/doclava/Stubs.java
index bc5e586..c0705df 100644
--- a/src/com/google/doclava/Stubs.java
+++ b/src/com/google/doclava/Stubs.java
@@ -1057,7 +1057,7 @@
     returnString = returnString.replaceAll("<", "&lt;");
     returnString = returnString.replaceAll(">", "&gt;");
     returnString = returnString.replaceAll("\"", "&quot;");
-    returnString = returnString.replaceAll("'", "&pos;");
+    returnString = returnString.replaceAll("'", "&apos;");
     return returnString;
   }