bug#2577: 23.0.91; startup.el should choose .emacs ahead of .emacs.elc if .emacs is newer

[Phil Hagelberg]

The specific failure is this:

A user keeps his entire .emacs.d in an SCM system. This includes not
only his personal customizations, (which would hardly benefit from
compilation) but third-party libraries that haven't made it into Emacs
proper yet. These third-party libraries are byte-compiled in every
checkout of the user's .emacs.d, which span multiple machines.

One of these libraries gets a bug fixed, so he installs the update and
checks it in. Now he moves to another machine that has his dotfiles
checked out, and he pulls in the update, but it's ignored in favour of
the out-of-date .elc file.

Everyone I know who uses Emacs seriously keeps their .emacs.d in an SCM
as well as third-party libraries, so I don't consider this much of an
edge case.

Ideally a flag would exist that could instruct Emacs to ignore
out-of-date .elc files. I understand this is not appropriate to submit
during a feature freeze, but saying it's not a problem is not helpful.

-Phil