Update rules_swift README.

PiperOrigin-RevId: 222405816

Get linker options from the C++ toolchain for Xcode builds when possi…

…ble.

This was previously only done for Linux toolchains, but the distinctions between apple_binary (which uses CROSSTOOL to link) and swift_binary (which doesn't fully use CROSSTOOL, yet) were causing problems for Apple targets under some circumstances (for example, test binaries and their bundle loaders).

PiperOrigin-RevId: 206822105

- Bump version number in README in anticipation of next release.

- Add instructions about configuring Clang on Linux.

RELNOTES: Linux users must set `CC=clang` in their environment.
PiperOrigin-RevId: 206804748

Fixes to support Bazel 0.14.1.

Fixes bazelbuild#15.

Add WORKSPACE to the //:for_bazel_tests target. (bazelbuild#18)

PiperOrigin-RevId: 200433540

Add Travis CI status badge and bump version number.

Add missing licenses declaration to the proto example.