Mostly forked from https://github.com/nsf/gocode Options for vim, emacs etc. cleaned.
Executing (MiddleMouseButton) 'compl' in tag window of existing .go file should insert at 'dot' and open +completions window. RightMouseButton on token in that window should insert. Undo surely works.
Closing +completion window should close client. Daemon should be closed explicitly. See README_original.md for detail (assuming 'Edit , x/gocode/ c/compl')