Fix another typo in README.md.
Useful error message if protobuf compiler is not installed
Merge pull request #3 from eagafonov/master

Useful error message if protobuf compiler is not installed
Don't allow protocol buffers to refuse restoring large backup data.
Merge branch 'master' of github.com:zbackup/zbackup
Make zbackup compile on OS X.
Merge pull request #7 from ikatson/osx-after-review

Make zbackup compile on OS X.