Fix build protoc script for windows

Change log for 3.0 GA release.

Make protoc-artifacts able to build plugins.

Fixes traivs cpp build.

Remove the use of INT64_C/UINT64_C and add static_cast when neccessary.

GA fixes

Bump version number for GA

We need to pick up some of the last-minute Ruby fixes.

Ruby: translate package names from snake_case -> PascalCase.

Add a script to build protoc zip packages.

[ci skip]

Change-Id: Ia0e0bf3bb6bd24633dc8f294318bb20ac837f8b9

Ruby: generated foo.proto -> foo_pb.rb instead of foo.rb.

Fixes https://github.com/google/protobuf/issues/823

Change-Id: I7f4c2bfcac2f81d8b34c030dd3d12ea02aaa2264

This brings us more into line with other langauges, and makes it more
obvious when we are requiring protobuf generated code.

Fix maven links.

Correctly sets the generate_for_named_framework option after parsing.

Ruby: encode and freeze strings when the are assigned or decoded.

Change-Id: I252d7a644a9e4064a9f1a816a2be3f25f37b4c43

 - Also updates the documentation with a bit more information.

Remove linux tests from travis.

Fix sign-comparison warnings and add a test for that.

[ci skip]

Change-Id: Ibefbdf441d932c5751235c635244450d7cbacc53

When it runs in parallel with other jenkins tests, multiple tests start
to fail probably because cpp_distcheck will update the C++ lib that
other tests (such as python_cpp) are depending on.

Change-Id: Ibca0243084bb6b81c811b62c75288e20cc2aabf5

These tests are already covered by jenkins and right now jenkins can
finish these tests much quicker then travis.

Change-Id: I5799761ccc338211d750940e3cf4c8e2569c8144