[REPLAY] Remove C-based Replay API

[REPLAY] Remove C-based Replay API

This is a huge commit, unfortunately, but it was not possible
to split it up easily without breaking the build.

This commit changes:

- Remove the 'const char* const* action' madness, replace by
  std::vector<string> (aliased as ReplayAction)
- Rename replay.c to replay.cpp
- Change CMake files
- Rewrite several macros to make them C++ compliant