Also made the Travis build ensure that no warnings
are present.

These builds were previously spewing many warnings,
which was hiding warnings for important things like
accidentally using C++11-only features.

Change-Id: I56caeee9db48bc78756a3e8d7c14874630627037

add default_runtime attribute to cc|py rules.

This adds implicit dependencies to the coressponding runtime libraries.

Use oneof case in equality tests

The included C# test will fail until the regenerated code is used, which is in the next commit.

Change the #include for any.h to use angle brackets instead of quotes

Change the #include for any.h to use angle brackets instead of quotes, to be consistent with other protobuf library includes.

Enable python bazel tests and explicit list python dependencies.

--strip_prefix doesn't seem to work.

Add runfiles to make the protobuf_test pass.

Rename python and java bazel rules.

Use && for internal_copied_filegroup.

So that the rule fails if one or more files cannot be copied.

Python bazel support

We need to use the list to indicate field presense.
The field must only contain 0 or 1 string element.

fix json_format for python2.6:

1, objcect_pair_hook is not supported in python2.6, so duplicated key check is removed in 2.6
2, total_seconds is not suppoted in python2.6, changed to compute seconds directly

Allow include to be None.

This enables the use case where all the paths are relative to the
workspace root, e.g.

foo/bar/BUILD
       /foo.proto -- package foo.bar

would generate the message correctly.

Fix typos in cmake README.md

In anticipation of PR #753 getting merged we'll change this back. However until that PR gets merged the old value "BUILD_TESTS" is really needed.

Improved CMake project

Extract protoc action into .bzl for cc.