Keeppos feature & stable release

1.0.0 2015-04-04

• Add keepCursor feature. |g:asterisk#keeppos|. This feature is based
  on @pelodelfuego's work! https://github.com/pelodelfuego
• Add test
• Fix minor bug and now it's stable

Thanks @pelodelfuego

https://github.com/haya14busa/vim-asterisk/blob/master/README.md#1-stay-star-motions-z-prefixed-mappings