convert cygdb to an distribute entry point
Merge pull request #229 from mindw/0.19.x

convert cygdb to a distribute entry point
fix some typos
Merge pull request #238 from mindw/0.19.x

fix some typos
enable support for yield in return expressions

--HG--
extra : transplant_source : %94%87%D7e%B9%82%EF%926%26o%C0%8E%0DcY%C3%E3n%DB
merge 0.19.x branch into master