PHP namespaces for nested messages and enums (#4536)

* uses namespaces for nested messages and enums

* fixes namespaces for PHP dist

* fixes namespace for Descriptors, adds Cardinality and Kind

* fixes nested namespaces for reserved words and adds tests

* adds tests and generator fix for php class prefixes

* fixes escaping of protobuf packages, enum comments, misc others

* nice refactor of generated code

* adds class files for backwards compatibility

* simplifies code with templates

* adds compatibility files to makefile

* cleanup of generator and fixes nested namespace bug

* regenerates proto types

* remove internal BC classes

* adds deprecated warning, adds methods back

* simplifies if statement

* fixes dist files

* addresses review comments

* adds back TYPE_URL_PREFIX constant

* adds @deprecated to old nested class files

* skips tests which require a separate process when protobuf.so is enabled

* Adds tests for legacy nested classes that do not require separate processes to test

* uses legacy names for GPBUtil message check

* adds block for IDE @deprecated message

* Namespace for nested message/enum in c extension

* Remove unused code

1 files changed, 1 insertions, 1 deletions

diff --git a/php/src/Google/Protobuf/NullValue.php b/php/src/Google/Protobuf/NullValue.php
index d4022ccc..482b80dd 100644
--- a/php/src/Google/Protobuf/NullValue.php
+++ b/php/src/Google/Protobuf/NullValue.php
@@ -9,7 +9,7 @@ namespace Google\Protobuf;
  * `Value` type union.
  *  The JSON representation for `NullValue` is JSON `null`.
  *
- * Protobuf enum <code>Google\Protobuf\NullValue</code>
+ * Protobuf type <code>google.protobuf.NullValue</code>
  */
 class NullValue
 {