Revert "Add Vim 8 job handler"

This reverts commit e441765, which was
accidentally pushed to the wrong branch.

Author: tpope

autoload/dispatch.vim

@@ -623,10 +623,6 @@ function! dispatch#compile_command(bang, args, count) abort
 
     if s:dispatch(request)
       call s:cgetfile(request)
-      if request.handler ==# 'job'
-        botright copen
-        wincmd p
-      endif
     else
       let request.handler = 'sync'
       let after = 'call DispatchComplete('.request.id.')'
@@ -862,9 +858,6 @@ endfunction
 
 function! s:cgetfile(request, ...) abort
   let request = s:request(a:request)
-  if !has_key(request, 'handler')
-    throw 'Bad request ' . string(request)
-  endif
   let efm = &l:efm
   let makeprg = &l:makeprg
   let compiler = get(b:, 'current_compiler', '')

autoload/dispatch/job.vim

@@ -33,7 +33,6 @@ endfunction
 
 if !exists('g:dispatch_handlers')
   let g:dispatch_handlers = [
-        \ 'job',
         \ 'tmux',
         \ 'screen',
         \ 'windows',