Log Message:
Update wip/vimb to vimb-2.8.

Changes:
- Added bang for :eval command to run JavaScript code silently.
- Added setting input-autohide to hide the input box if it's empty.
- Added setting statusbar to toggle visibility of the status bar.
- Added autocmd feature.
    - completion for :autocmd and :augroup
    - autocmd events for downloads
    - curly brace pattern matching for auto commands
    - unit tests for pattern matching 
    - don't put autocmd commands into history
- Added feature to read page content from stdin. Thanks to Hironao Komatsu for
  this nice patch.
- Fixed wrong showcmd in status bar if there exists a keybinding beginning
  with chars that needs more keys.
- Fixed a little memory leak in unmap logic.
- Show the number of search results in status bar.
- Fixed download with content-range header. If the server responds with an
  Accept-Range header without content the download was not started or was
  considered as failed.
- Don't apply CTRL-V to pass through mode.
- Allow to use shortcut also if query contains '://'.
- Allow :normal and :eval commands to contain '|' char.