Add -explorer-columns
Add action options
Improve documentation
Add sort_type option
Fix #219 explorer toggle problem
Fix #222 choosewin problem
Fix #223 explorer behavior
#223 add parent option
Improve explorer columns behavior
Fix #224 hide buffer problem
Add exposed vimfiler#do_switch_action
Merge pull request #226 from jpanganiban/master

Add exposed vimfiler#do_switch_action
Correct ignore_pattern's regexp example
Merge pull request #229 from rafi/feature/doc

Correct ignore_pattern's regexp example
Fix #228 add b:vimfiler check
Redraw screen when sorting
Use manual redraw in sort action.
Fix #231 improve parent directory
Improve default drive value
Fix prompt problem