Changed transition_table_cell_t from std::tuple<const State, std::string> >
to std::tuple<const State, std::vector<symbol_t> > and a likewise change to
transition_table_content_t.
Finished multitape machine file parsing and execution.
Fixed a bug where the header was not positioned properly if the
tape size had been increased left.
Added libjson_spirit cpp files and CMakeLists.txt files so it can
be compiled along the rest of the project.