Even though we disable warnings when building jsoncpp itself, including
its headers from other CMake sources may still cause warnings.
Additional work will be needed to port CMake to newer jsoncpp interfaces
while still supporting jsoncpp 1.0.0. For now, just suppress the
markup.
Even though we disable warnings when building jsoncpp itself, including
its headers from other CMake sources may still cause warnings. Update
the code to remove these -Wdocumentation warnings.
