Adds pkg-config (`.pc`) files for CMake based installs.

Adds pkg-config (`.pc`) files for CMake based installs.

Add implementations of open(2), mkdir(2), stat(2),
etc. that support long paths under Windows (paths
longer than MAX_PATH in <windows.h>, which is 260
characters).

The implementations are in a separate namespace
(google::protobuf::internal::win32), so they won't
collide with the standard implementations in
<io.h>, but after importing them with `using` they
can be drop-in replacements.

Fixes https://github.com/bazelbuild/bazel/issues/2634
Fixes https://github.com/google/protobuf/issues/2891

install 'generated_message_table_driven.h' and 'metadata_lite.h', they are included when compiling the files generated using protoc.exe 3.3.0

tested only on windows with visual studio 2015 as generator

Unfortunate typo. Just one extra ',' symbol, has led to the hidden implicit behavior.

Now everything will be fine.

This allows the file path to contain spaces which is very common on
windows.

> warning C4309: static_cast': truncation of constant value

introduced in commit 9db5b11c

the deprecated atomics.

The check target did not depend on the test_plugin binary, so this would
cause "make check" to fail at times because of the absence of
test_plugin. This change adds a dependency on test_plugin so that it
will always get built before the tests are executed.

Until now this file was just checked into the repo, but actually it
should be generated from any.js, struct.js, and timestamp.js. This
change updates the build system to make this happen. To make it work I
also had to remove some C++11 features from embed.cc.