This is taking an approach of putting all the logic in JsonFormatter. That's helpful in terms of concealing the details of whether or not to wrap the value in quotes, but it does lack flexibility. I don't *think* we want to allow user-defined formatting of messages, so that much shouldn't be a problem.

Simpify json tests

Fix C# JSON field ordering

Fix build failure on Windows when Unicode build is enabled.

Fix trivial bug in field orderings.

Use ' instead of " in the expected JSON, then replace it before asserting.

(Shows the benefit of unit testing even code "too simple to fail"...)

Well-known type operations for Timestamp and Duration

While I've provided operators, I haven't yet provided the method equivalents. It's not clear to me that
they're actually a good idea, while we're really targeting C# developers who definitely *can* use the user-defined operators.

Handle field names of "descriptor" and "types".

This is a follow up CL for e9abc404,
which breaks build when UNICODE macro is defined.

protoc has explicitly called MBCS version of APIs / funcsions
rather than UTF-16 (wchar_t) version of them regardless of
UNICODE macro definition (and it indeed works as expected).
Hence it makes sense to call GetModuleFileNameA explicitly.

Expose GetUmbrellaClassName in csharp_names.h

Merge C# proto3 from csharp-experimental to master

Throw on null for string/bytes single fields

Rename ThrowHelper to Preconditions and make it public - we'll want to use it from the generated code soon.

Additionally, change it to return the value passed, and make it generic with a class constraint.
A separate method doesn't have the class constraint, for more unusual scenarios.

Remove a few hangers-on from frozenness.

Remove the C# Freeze API

Expose IsClientStreaming and IsServerStreaming in MethodDescriptor

Move the definition of GOOGLE_FALLTHROUGH_INTENDED to port.h

On x64 MSVC platform, macro PROTOBUF_LITTLE_ENDIAN won't be set

First attempt at using profile 259 for Google.Protobuf.

- Fix nupec paths
- Remove an obsolete part of the JSON build
- Add documentation and tests to reflection extension methods, and improve implementations

Update minimal ios and osx version for deployment.

Remove two unused functions.