* rewrite int128 long divison to avoid stackoverflow hit

Protobuf was showing Stackoverflow hits in the code base, primarily code written to calculate long division. This code was copied from a stackoverflow post, which means it would be licensed under CC BY-SA 3.0. Due to this license, IBM Legal did not want to include this OSS in our products and advised us to re-write this particular piece of code to avoid the license restriction. We have re-written the code for our own distribution, and are willing to merge it into the main code base for others who want to avoid the stackoverflow license issues to benefit as well.

cmake: protobuf_generate fix GENERATE_EXTENSIONS, fix DEPENDS, add PROTOC_OUT_DIR

Fix 4615

The problem is that sched_yield is available on the target, but configure.ac is asking to build
a host binary using the AC_SEARCH_LIBS macro.  It can't configure for Android, since sched_yield isn't
available on the host.

Fix undefined behavior in hash function.

Fix issue with version.rc

Fix appveyor documentation

Fix python install, cat java error log for kokoro build

* Adopt php_metadata_namespace in php code generator

The php_metadata_namespace is corresponded to the relative directory of
the metadata file. e.g., previously, the metadata file of foo.proto was
GPBMetadata/Foo.php. If the php_metadata_namespace is "Metadata\\Bar",
the metadata file will be Metadata/Bar/Foo.php.

* Handle empty php_metadata_namespace

Signed integer overflow creates undefined behavior that may lead to unpredictable fails on different platforms.
One known example of the hardware where this code did fail is Apple A6 (32-bit Apple Swift CPU)

16777619, 16777499 - two prime numbers that typically used to get better dispersion.

Include version information in Windows binaries #3380

Appveyor MinGW build

[Java] Remove unsafe no-copy String allocation since it's not useful in rece…

Add .proto files to extract_includes.bat

* Throw error if user want to access message properties

* Fix typo

* Avoid direct check of class name

So that subclasses are also ok

* Use type hint in function signature.

use brew instead of easy_install in OSX (easy_install keep failing for a month)

Fix error in Clang UndefinedBehaviorSanitizer

Pointer Arguments to memcpy can not be null in UndefinedBehaviorSanitizer.
In this case, both the memory and the size was zero. This change allows
protoc to run under UndefinedBehaviorSanitizer.

Add mention to the "Build" section of the ReadMe of the requirement of installing an optional component to VS2017.

Fix MinGW build

Fix CMake build on Cygwin.

Make RepeatedField#delete_if consistent with Array#delete_if.

The class name was linked to the next word in the sentence.
"User\UserRequestis not found in descriptor pool."

Add a third-party RPC implementation: raster

* Fix memory leak of exceptions raised by RaiseException()

Currently exceptions raised by RaiseException() is never deallocated because:

* ARC is disabled for this library: https://github.com/google/protobuf/blob/master/BUILD#L913
* It is constructed with `+alloc` but is never `-release`d.

This change fixes the issue by using `-[NSException exceptionWithName:...]` instead, which returns an autoreleased instance, so it is deallocated properly.

* Fix format.