Add support for :cq

[m1foley]

In Vim, :cq works like :qall! except that Vim returns a non-zero exit code. A common use is when writing a git commit message, :cq is used to abort the commit (whereas :q! exits with a success code and commits with the default message).

In Wasavi, I'd expect :cq to behave identically to :q!.

[dkarter]

Agree, I found myself accidentally typing that in Wasavi. At the very least it would be nice to have cmap / cnoremap to allow adding this as an alias in the vimrc.