set version to 0.18rc1
Fix overflow_check CompileError with msvc

--HG--
extra : transplant_source : %3FH%B6t%1FFL%D8%2BF%7CV%7D%10T9%EA%CB%A0%00
merge 0.18.x branch into master
Added tag 0.18rc1 for changeset 9a11631e0edb