std: Fix search-and-replace typos
rustpkg: Extract version number from git, as per #5684

For now, the test I added just checks that PkgId::new parses the
version number out of a git repo's tags list, where relevant.
fix decoding of multiple attributes (fixes #7017)

We were just looking at the last because we were overwriting ret.
add test for RcMut being Const and Owned, tests #7017 being fixed
auto merge of #7018 : bill-myers/rust/fix_7017, r=thestinger

Minimally fixes #7017, we were overwriting the result and thus ignoring attributes before the last.

csearch::get_item_attrs and decoder::get_item_attrs should probably also be changed to each_item_attrs using the for protocol, but that's just a minor performance/style issue.
remove deprecated vec::{is_empty, len} functions
auto merge of #7023 : thestinger/rust/vec, r=brson
librustc: Allow adding static fn's in multiple impl's.
Add test for #4228.
rustpkg: Accept package IDs like github.com/foo/bar#0.3

If the package ID is of the form s#v, where v is a valid version
string, fetch tag v of that package.
auto merge of #6904 : catamorphism/rust/rustpkg_version_vcs, r=catamorphism

r? @brson
auto merge of #7029 : luqmana/rust/issue-4228, r=catamorphism

Fixes #4228
Deny common lints by default for lib{std,extra}