Users may want to use a different $EDITOR for quilt and for other tasks.
The quilt "mail" and "header" commands already support that, you just
have to add an "EDITOR=foo" line in ~/.quiltrc. However I was surprised
to notice that it doesn't work with the command that would need it the
most: "edit". The reason is that quilt/edit doesn't source patchfns like
all other functions do, and the reading of ~/.quiltrc happens there.
Thus, I would propose that we now source patchfns in edit.
We could probably go with something faster, as we only need to source
~/.quiltrc and not the whole patchfns. However, it would duplicate some
code and increase the maintenance cost for a speed benefit that is
hardly measurable, so I don't think it's worth the additional effort.
And we are likely to need some of the patchfns functions in the edit
functions in the future anyway.