Remove references to SoyFileSet and compileTemplates() from soy docs
these apis are discouraged
Also remove a weird page called adv-protos.md which appears to have been half written
@@ -7325,7 +7325,8 @@ goog.object.setIfUndefined = function(obj, key, value) {
* object will not be changed and the function will not be called (the function
* will be lazily evaluated -- only called if necessary).
*
- * This function is particularly useful for use with a map used a as a cache.
+ * This function is particularly useful when used with an `Object` which is
+ * acting as a cache.
*
* @param {!Object<K,V>} obj The object to which to add the key-value pair.
* @param {string} key The key to add.
