devel/toml11: new port - C++11 header-only parser/encoder

It is compatible to the latest version of TOML v1.0.0-rc.2, and one of
the most TOML-standard compliant libraries, with great error messages,
configurable serializer, user-defined type conversions, and with full
UTF-8 support.

WWW: https://github.com/toruniina/toml11

Sponsored by: SkunkWerks, GmbH