less: simplify 1.2 errorformat and split errorformat up
less: simplify 1.2 errorformat and split errorformat up

* remove some unneeded escaping of spaces and colons from the 1.2
  errorformat
* split the pre and post 1.2 errorformats up and comment them for future
  clarity

wezhang/vim-setup,wezhang/vim-setup,wezhang/vim-setup,wezhang/vim-setup,nikmartin/dotfiles,wezhang/vim-setup,wezhang/vim-setup