Changed layout of the html tampering lesson and fixed some JavaScript issues. Added a small mitigation page.

Moved the lessons concerning client side validation to client side category

webgoat-lessons/bypass-restrictions/src/main/java/org/owasp/webgoat/plugin/BypassRestrictions.java

@@ -38,7 +38,7 @@ import java.util.List;
 public class BypassRestrictions extends NewLesson {
     @Override
     public Category getDefaultCategory() {
-        return Category.PARAMETER_TAMPERING;
+        return Category.CLIENT_SIDE;
     }
 
     @Override