Vec<T> should be in the collections module

[thestinger]

From a user's point of view, not having all the collections in the same place is very strange. The standard library is going to need vectors and will likely needs maps and sets in the future, so having the collections crate separate is a problem.

[pnkfelix]

Won't fix, the growable Vec<T> is such a crucial component that it needs to be in libstd.

(its possible that what we currently call libstd may be revised/renamed to something else to reflect it more minimal nature. But the point is that Vec<T> is fundamental in ways that maps and sets are not.)

[thestinger]

It being available in libstd doesn't exclude it from being re-exported in the collections module. If and when the standard library needs more containers, it would be a backwards incompatible change to simply move them to the standard library without leaving re-exports anyway.

[aturon]

This issue is now subsumed by the facade effort, which is slated to add vec to libcollections, with libstd reexporting it.

I'm closing in favor of that issue.