librustc: emit loop for expr_repeat instead of 2n instructions in [x, ..n]
Kill some warnings: unused imports and old #[deny(..)]s.
libcore: implement `str::each_char_reverse` correctly.

Previously, `each_char_reverse` was not iterating at all, so the
testcase never ran properly.
treemap: add a find_mut method
librustc: clean-up expr_repeat loop generation: use native integers
hashmap: add find_mut method
trie: add find_mut method
smallintmap: add find_mut method
expose find_mut in the Map trait
trie: improve docstring
rustdoc: Show purity
configure: error on unsupported target-triples and arm-linux-androideabi fix
kate: remove `const`, `log`, and `pure` keywords, add `super` keyword
configure: simplify pandoc version recognition.

The version recognition was failing for version 1.11, thinking the
minor version was 1 rather than 11.
core: Fix doc comment error, as per #4983
make ty_region give a useful span when it fails
Expand on cleanups in trans for expr_repeat and add to tests.
auto merge of #5524 : luqmana/rust/repeat-loop, r=pcwalton

`let v = [24, ..1000];` now more or less emits the same IR as:

```Rust
let mut i = 0;
while i < 1000 {
    v[i] = 24;
    i += 1;
}
```

LLVM will still turn it into a memset if possible with optimization on.
auto merge of #5525 : dbaupp/rust/minor_fixups, r=graydon

Kills some warnings, and implements str::each_char_reverse so that it actually iterates. The test case wasn't detecting a failure, since the loop body was never executed.
auto merge of #5528 : thestinger/rust/find_mut, r=brson

This currently requires workarounds for the borrow checker not being flow-sensitive for `LinearMap` and `TrieMap`, but it can already be expressed for `TreeMap` and `SmallIntMap` without that.