Add neocomplete configurations

ref. https://github.com/Shougo/neocomplete.vim/tree/89732f78983f568308aa1f3426ff54bcf031ed84#configuration-examples
Use neosnippet

ref. https://github.com/Shougo/neosnippet.vim/tree/a7c05372bad5408ab3e87851330bbac4b5a646fd#neobundle
Add neosnippet configurations

ref. https://github.com/Shougo/neosnippet.vim/tree/a7c05372bad5408ab3e87851330bbac4b5a646fd#configuration