Adding LICENSE file for Boost and MIT.

This licenses the files lying under the path
launchers/macosx/obj-cpp/include in this repository.

launchers/macosx/obj-cpp/include/neither is MIT, while the
rest unless spesified in the header, is Boost.

C++17 variant, eggs implementation is licensed under Boost,
original source can be found at http://eggs-cpp.github.io/variant/
forked at: f801e971d054341430cb91d79aa0bb4d0bf24330

C++ Neither is licensed under MIT, original source can be found at
https://github.com/LoopPerfect/neither
forked at: a2bbaa25d62c538fb044a6eda5254e7a068e4ff7

C++ Optional implementation is licensed under Boost, original source
found at https://github.com/akrzemi1/Optional
forked at: f6249e7fdcb80131c390a083f1621d96023e72e9