code format by clang-format

Merge remote-tracking branch 'refs/remotes/origin/optimize_convertibl…

…e_register_helper'

Merge branch 'refs/heads/pr/34'

# Conflicts:
#	include/kaguya/metatable.hpp
#	test/test_02_classreg.cpp

fixed typo

Merge branch 'master' of https://github.com/satoren/kaguya

push nil if shared_ptr has null

add script for generate of one header file