Fix #523 rec/async behavior
Fix #529 post_filters error
Fix jump_list open action
doc/unite.txt: wording/clarity/brevity
Merge pull request #534 from justinmk/update_doc

doc/unite.txt: improve SOURCE ATTRIBUTES section
add g:unite_vertical_preview switch
This adds a configuration option to open the preview window with the
file kind in a vertical split.
Merge pull request #533 from smackesey/add_vertical_preview

add g:unite_kind_file_vertical_preview