error_handle

 Changes to be committed:
	new file:   assert.hpp
	new file:   deploys/error_handle.hpp
	new file:   deploys/error_type.hpp
	new file:   deploys/error_writer.hpp
	modified:   envs/nowadays.hpp
	new file:   sync/single_entry.hpp
	new file:   utt/cases.hpp
	new file:   utt/icase.hpp
	new file:   utt/main.cpp