[vim] Add parens around piped source commands (#1029)
[vim] Add parens around piped source commands (#1029)

Previously a command like `echo a && echo b` would get transformed into
`echo a && echo b | fzf`, which only pipes the output of the second
command. Adding parentheses around the source command avoids this issue,
and works on both Unix and Windows.
janlazo/fzf,stuha/wbr-zsh,wilywampa/fzf,junegunn/fzf,junegunn/fzf,junegunn/fzf,infokiller/fzf,janlazo/fzf,wilywampa/fzf,infokiller/fzf,janlazo/fzf,wilywampa/fzf,infokiller/fzf