improve features
  - improve auto quickfix open when 'open in new tab'
    - restore view(cursor position, scroll..) of quickfix window to auto-opened quickfix window
    - restore size of quickfix window to auto-opened quickfix window
    - now you don't need to provide g:qfenter_copen_modifier option. QFEnter now smartly determine whether the new quickfix window is botright or topleft, vertical or horizontal.
  - change g:qfenter_ttopen_map option name to g:qfenter_topen_map (backward compatibility maintained)
  - remove '<Tab><Tab>' from default mapping