Building the protobuf compiler with Bazel fails to resolve the unqualifed "string"s in java_options.h:

```
ERROR: .../external/com_google_protobuf/BUILD:248:1: C++ compilation of rule '@com_google_protobuf//:protoc_lib' failed: Process exited with status 1 [sandboxed].
In file included from external/com_google_protobuf/src/google/protobuf/compiler/java/java_context.h:41:0,
                 from external/com_google_protobuf/src/google/protobuf/compiler/java/java_enum_field_lite.cc:38:
external/com_google_protobuf/src/google/protobuf/compiler/java/java_options.h:59:3: error: 'string' does not name a type
   string annotation_list_file;
   ^
external/com_google_protobuf/src/google/protobuf/compiler/java/java_options.h:62:3: error: 'string' does not name a type
   string output_list_file;
   ^
Use --strategy=CppCompile=standalone to disable sandboxing for the failing actions.
INFO: Elapsed time: 41.487s, Critical Path: 6.20s
//interpreter:eval_test                                               NO STATUS

Executed 0 out of 1 test: 1 was skipped.
```

Update commit id to upload latest composer.
Compile php with bc-math for future json support.

* Follows proper autoloading standards
 - Splits PHP classes in descriptor.php into separate files
 - Splits MapFieldIter and RepeatedFieldIter into separate files
 - Moves descriptor.php to Internal/functions.php
 - Moves all namespaced functions into Iternal/functions.php

* fixes Makefile.am for added php files

* [PHP] moves all functions to GPBUtil

* removes description.php from the makefile

Add tvOS to the podspec.

Fixes https://github.com/google/protobuf/issues/3217

Export symbols used in inline functions

fixed_address_empty_string symbol is used in an inline function.
We have to export it to avoid undefined reference link errors.

Ensure that for Java, imports of .proto files with empty packages works

Add continuous testing config files for Kokoro

Add MacOS and Linux tests to Kokoro

ObjC: Preserve unknown fields in proto3 syntax files.

Refactor cc options in BUILD file for Windows

CMake: Add modern protobuf_generate

As announced: https://groups.google.com/forum/#!topic/protobuf/VX5qEmTW3y0

The ObjC side of https://github.com/google/protobuf/issues/272

Properly error on a tag with field number zero.

Fix CMake version check

* Add new file option php_namespace.

Use this option to change the namespace of php generated classes.
Default is empty. When this option is empty, the package name will be
used for determining the namespace.

* Uncomment commented tests

* Revert gdb test change

* Update csharp descriptor.

* Add test for empty php_namespace.

This fixes a compiler bug that caused a Java syntax error when one .proto file
would import another one with an empty package and java_package. This fixes
issue #3114.

Optimize GPBDictionary.m codegen to reduce size of library

Fix some cases of reading of 64bit map values.

Fixes https://github.com/google/protobuf/issues/3164.

Don't put gcc warnings options in copts, so that protobuf is able to
build by MSVC toolchain without python wrappers.

* not to use std::random_device for map.Seed().

* remove include random

Add headers as part of cmake project generation

tested only on windows with visual studio 2015 as generator

Improve fix for https://github.com/google/protobuf/issues/295