[PATCH 0/1] Add support for `destination' specification in egg files

[Evan Hanson]

Hi folks,

Someone noted on IRC that the `destination' specification for egg files
is currently documented but not actually implemented. I also noticed
this when trying to install a man page into <PREFIX>/share a few weeks
ago, and prepared the attached patch, but I never got around to sending
it. So, here you go.

Most of the machinery to support this specification was already there,
it just needed an entry in `egg-info-items' and a bit of validation.

This patch only allows files to be installed under CHICKEN_INSTALL_PREFIX,
which works for my use case and seems like a sensible behaviour, but
might not be right. I'm also not sure about the use of `default-prefix'
here, I have just followed the examples of the existing code despite the
"XXX wrong!" warnings because I don't know any better. (ISTM that value,
which is currently defined as C_INSTALL_PREFIX, should perhaps rather be
C_TARGET_PREFIX to match the other "default-foo" definitions? But that
might be a tangent.)

For your consideration, just wanted to get this out there based on the
IRC convo.

Best,

Evan