Adds The Factory to PoweredByMesos documentation.
Added docker container prefix to docker docs.

Review: https://reviews.apache.org/r/26052
Kill <stout/preprocessor>.
Update defer.hpp and deferred.hpp
Shouldn't need the void case.
Factor out defer.hpp
More refactoring.
More.
Another.
Keep going.
Aw yeah.
really?
maybe?
Disambiguate replica.cpp.
static_assert.
Update executor.hpp.
Add LICENSE to memory.hpp.
Update run.hpp.