Merge pull request #49 from crazymaster/master

Add text mode filetypes
Fixed call vital#of().
Merge pull request #50 from osyo-manga/fix_vital_of

Fixed call vital#of().
- Deleted unnecessary variables.
- Improved for vital.
- Improved vital initialization.
- Fixed s:V.
- Improved cache current line behavior.
- Fixed file source behavior.
- Fixed neocomplete#system().
- Improved neocomplete#system().
Update doc