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, 2 insertions, 2 deletions

diff --git a/php/tests/php_implementation_test.php b/php/tests/php_implementation_test.php
index 6481473e..323a36ff 100644
--- a/php/tests/php_implementation_test.php
+++ b/php/tests/php_implementation_test.php
@@ -5,7 +5,7 @@ require_once('test_util.php');
 
 use Foo\TestEnum;
 use Foo\TestMessage;
-use Foo\TestMessage_Sub;
+use Foo\TestMessage\Sub;
 use Foo\TestPackedMessage;
 use Google\Protobuf\Internal\CodedInputStream;
 use Google\Protobuf\Internal\FileDescriptorSet;
@@ -527,7 +527,7 @@ class ImplementationTest extends TestBase
 
     /**
      * @expectedException Exception
-     * @expectedExceptionMessage Expect message.
+     * @expectedExceptionMessage Expect Foo\TestMessage_Sub.
      */
     public function testArraysForMessagesThrowsException()
     {