Reenable cocoapods objc test and remove unnecessary workaround for rvm

Update xcode version support and travis usage

- Add entries to objectivec/DevTools/full_mac_build.sh
- Support `-quiet` via an option on full_mac_build.sh. NOTE: we don't use
  this on travis because the lack of output for a long time could cause travis
  to kill the build (when we get a slow VM).
- Update travis config to use newer images.

Update third_party.md

Missed in #2467.

Updated the location for `protobuf-maven-plugin`

C++: export _xxx_default_instance_ symbols

Add missing include in embed.cc

oneOf fix for JsonFormat includingDefaultValueFields

1. Generate single file for each message.
2. Lazily initiate metadata.

Improve ObjC deprecated annotation support.

Include -std=c++11 when compiling protobuf if available.

- Check the parent file options for deprecation when deciding to tag Messages
  and Enums as deprecated.
- Within the generated source push/pop the warning for implementing deprecated
  things around a deprecated class implementation.
- Annotate the methods generated for extension fields as deprecated.
- Add a testing .proto file that covers deprecated fields, messages, enums,
  enum values and compile it into the unittests to confirm things compile
  cleanly.
- Add a testing .proto file that uses the file level option to make everything
  deprecated and compile it into the unittests to confirm things compile
  cleanly.

_xxx_default_instance_ symbols are used in inline functions. We have
to export them to avoid undefined reference link errors.

This changes fixes "use of undeclared identifier 'assert'"
compilation error.

Send all protobuf logging to logcat by default on Android

Currently the default for protobuf on Android is to silently drop all log
messages. This makes debugging difficult because things like GOOGLE_LOG(FATAL)
will crash the process without actually logging a useful error.

This CL changes the logging so that by default we send messages for all log
levels to logcat (and stderr). Users can override this by setting
GOOGLE_PROTOBUF_MIN_LOG_LEVEL. Also, that option was not being respected for
non-Android platforms so I went ahead and fixed that to make things consistent.

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.

Add version number to plugin protocol.

OpenBSD correct endianess handling

Add missing files.

* Factored Conformance test messages into shared test schema.

* Updated benchmarks to use new proto3 message locations.

* Fixed include path.

* Conformance: fixed include of Python test messages.

* Make maven in Rakefile use --batch-mode.

* Revert changes to benchmarks.

On second thought I think a separate schema for
CPU benchmarking makes sense.

* Try regenerating C# protos for new test protos.

* Removed benchmark messages from test proto.

* Added Jon Skeet's fixes for C#.

* Removed duplicate/old test messages C# file.

* C# fixes for test schema move.

* Fixed C# to use the correct TestAllTypes message.

* Fixes for Objective C test schema move.

* Added missing EXTRA_DIST file.

Add a proto_lang_toolchain() for cc_proto_library

Bazel's built-in cc_proto_library rule uses a proto_lang_toolchain to learn how to invoke proto-compiler.
To use Bazel's cc_proto_library, add the following to your project's WORKSPACE file:

local_repository(
  name = "com_google_protobuf_cc",
  path = "/path/to/protobuf-distribution/"
)

Change CodedInputStream#DEFAULT_SIZE_LIMIT from 64MB to

Integer.MAX_SIZE (0x7FFFFFF) #2228

M java/core/src/main/java/com/google/protobuf/CodedInputStream.java
 Set DEFAULT_SIZE_LIMIT to Integer.MAX_SIZE (Was 64MB). This is how it was
 in pre-2.7.0 pb. Changed size check to an overflow-conscious test (as it
 is later in tryRefillBuffer (making sizeLimit a long was to disruptive).

M java/core/src/test/java/com/google/protobuf/CodedInputStreamTest.java
 Add two tests that echo tests recently added over in c++ to test parse
 of message sizes that are approach and are beyond the size limit.

Add a swift_prefix file option.