Refactored int/uint range code in preparation for change to range_rev semantics.

Also added unit tests of range code to test refactoring.  The
num-range-rev.rs test will need to be updated when the range_rev
semantics change.
Switch over to new range_rev semantics; fix #5270.
Fix #5270: another test I did not update properly.
cmp: Use default methods in trait Eq, require only Eq::eq
auto merge of #7799 : blake2-ppc/rust/eq-default, r=sanxiyn

Let Eq::ne be implemented to the inverse of eq by default.
testsuite: Add xfailed test case for #6128
auto merge of #7802 : catamorphism/rust/issue-6128, r=catamorphism
rustpkg: Handle local git repositories

rustpkg can now build code from a local git repository. In the
case where the local repo is in a directory not in the RUST_PATH,
it checks out the repository into a directory in the first workspace
in the RUST_PATH.

The tests no longer try to connect to github.com, which should
solve some of the sporadic failures we've been seeing.
auto merge of #7681 : catamorphism/rust/rustpkg-local-repos, r=catamorphism

r? @graydon rustpkg can now build code from a local git repository. In the
case where the local repo is in a directory not in the RUST_PATH,
it checks out the repository into a directory in the first workspace
in the RUST_PATH.

The tests no longer try to connect to github.com, which should
solve some of the sporadic failures we've been seeing.
std: add consuming iterators for `HashMap` and `HashSet`
auto merge of #7806 : apasel422/rust/hash_consume, r=catamorphism

This partially addresses #7719.
ringbuf: Implement DoubleEndedIterator
auto merge of #7808 : blake2-ppc/rust/ringbuf, r=thestinger
hashmap: Remove .mutate_values() which is replaced by .mut_iter()
hashmap: Iterators for hashset diff, sym. diff, intersec, union

Implement the difference, union, etc iterators with the help of a custom
iterator combinator with explicit closure environment. Reported issue #7814
to be able to use the std::iterator filter combinator.
auto merge of #7815 : blake2-ppc/rust/hashmap-iterators, r=huonw

Implement set difference, sym. difference, intersection and union using Iterators.

The set methods are left since they are part of the Set trait. A grep over the tree indicates that the four hashset operations have no users at all.

Also remove HashMap::mutate_values since it is unused, replaced by .mut_iter(), and not part of a trait.
remove headers from unique vectors
auto merge of #7816 : thestinger/rust/header, r=huonw

Note that the headers are still on `~[T]` when `T` is managed. This is continued from #7605, which removed all the code relying on the headers and removed them from `~T` for non-managed `T`.
syntax: make a macros-injection pass; conditionally define debug! to a noop based on cfg(debug).

Macros can be conditionally defined because stripping occurs before macro
expansion, but, the built-in macros were only added as part of the actual
expansion process and so couldn't be stripped to have definitions conditional
on cfg flags.

debug! is defined conditionally in terms of the debug config, expanding to
nothing unless the --cfg debug flag is passed (to be precise it expands to
`if false { normal_debug!(...) }` so that they are still type checked, and
to avoid unused variable lints).
Update the ordering algorithm to semver 2.0.0.

Note that Version's `le` is not "less than or equal to" now, since `lt`
ignores build metadata. I think the new ordering algorithm satisfies
strict weak ordering which C++ STL requires, instead of strict total
ordering.