libcore: remove default to_str implementations for pointer types

These couldn't be overridden and so ended up being quite restrictive. This has
the side effect of changing the stringification of ~vecs, but nothing in
relied on this. Closes #4869.
Fix typo in grammar: underscore, not minus, can appear amongst hex digits.
Fix: now sha1 result_str() return correct value
Added ToStr implementations for &[T] and @[T]
rt: Make some runtime calls work outside of task context
auto merge of #5145 : Kimundi/rust/incoming, r=catamorphism
auto merge of #5140 : yjh0502/rust/issue_4458, r=catamorphism

Fix is a bug fix for issue #4458.

This patch is quite straight-forward. A test for result_str() is added.
Introduce lifetime declarations into the lists of type parameters.

Major changes are:
- replace ~[ty_param] with Generics structure, which includes
  both OptVec<TyParam> and OptVec<Lifetime>;
- the use of syntax::opt_vec to avoid allocation for empty lists;

cc #4846
auto merge of #5149 : brson/rust/rt, r=brson

Just a few minor things required for freestanding Rust.
auto merge of #5141 : nikomatsakis/rust/region-syntax-expl-lifetimes, r=nikomatsakis

Major changes are:
- replace ~[ty_param] with Generics structure, which includes
  both OptVec<TyParam> and OptVec<Lifetime>;
- the use of syntax::opt_vec to avoid allocation for empty lists;

cc #4846

r? @graydon
auto merge of #5106 : pnkfelix/rust/fix-docs, r=graydon

...s.  I freely admit I have not run a "make check" on this (trivial) change.
auto merge of #5098 : pkgw/rust/pr/issue4869, r=brson

See issue #4869. I'm not quite sure what constitutes "consensus from the core team" (cf. discussion in the issue), but this at least demonstrates that the proposed change is pretty straightforward.

After this change, there are no new test failures. I've un-ignored the `to_str` vectors test; it's not at all obvious to me why it'd be problematic, and it passes on my Linux machine.
Fix leaking non-public 'use' statements with glob imports

Working on #4366
Fix leaking immediate children and types via glob imports

More work on #4366
Fix implicit leaks of imports throughout libraries

Also touch up use of 'pub' and move some tests around so the tested functions
don't have to be 'pub'

Closes #4366