"make google/protobuf/stubs/pbconfig.h" was added in hope of addressing
the issue that when you "make protoc" from a freshly checked out
project, pbconfig.h will be reported missing. However, the trick doesn't
seem to work. Instead, add instructions in the document to work the issue
around.
Also document why MSYS2 cannot be used for publishing protoc.
1. make google/protobuf/stubs/pbconfig.h before making protoc, otherwise it
won't build a freshly checked-out code.
2. Document the build environments that have been tested to work.
3. Add support for MINGW64
release.
- Do not close the staging repository automatically
- Added staging.repository property
- Updated README with instructions for deployment
- Fix building 32-bit Mac artifact
