Sometimes there will be multiple packages in the same repository that
depend on each other, so we shouldn't tell el-get to go look for them in
another repository.
Move more variables to el-get-custom.el, add requires or
declare-functions as needed.
There were a few places that appeared to be actual bugs: wrong or
missing variable names.
flet is marked obsolete in 24.3 resulting in quite a lot of annoying
messages. The intended replacement is cl-flet, but that is unavailable
in earlier emacsen, so we can't use that either.
