Add Windows build documentation

- fix SIGUSR1
- generate lua_sandbox.go with cmake
Cleanup the Mac build

- use strlen instead of strnlen
- extern the circular buffer constants in the header
Merge branch 'versions/0.2'
Fix the version and ignore the generated lua_sandbox.go file
Merge pull request #171 from mozilla-services/windows_build

Windows build
Free the pack up to be used again in TcpOutput
Free the pack up to be used again on error in TcpOutput
Merge pull request #186 from tosh-iba/master

Free the pack up to be used again in TcpOutput
Change version # on master branch to reflect that it's still tied to 0.2 releases.
Merge branch 'master' into versions/0.2