Requirement of :chistory should require setting qf title?

[blueyed]

In https://github.com/tpope/vim-dispatch/commit/9096c8bba04046a18d252bb21dabec3bb3fedbbe was added to require :chistory (added in v7.4.2049, vim/vim@f6acffbe8).

In 13f2aa8 if exists(':chistory') is used to call setqflist([], 'r', {'title': …, but this is only available with has('patch-7.4.2200') vim/vim@d823fa910.

So at least the handling of the title should have a check for patch-7.4.2200.

For reference of some important patches: https://github.com/neomake/neomake/blob/852029b49c495181c2900d6baf4de7208507649e/autoload/neomake/list.vim#L5-L9

[tpope]

I would add let s:quickfix_info = has('patch-7.4.2200') and use that to replace all exists(':chistory') conditionals.