Remove vec::{rfind, rfind_between, find_between}, replaced by slices and iterator adapators.
Remove vec::[r]position_between, replaced by slices & iterators.
Convert vec::{rposition, rposition_elem, position_elem, contains} to methods.
Convert vec::{reverse, swap} to methods.
etc: update etc/unicode.py for the changes made to std::unicode.
Convert vec::{bsearch, bsearch_elem} to methods.
Convert vec::dedup to a method.
Convert vec::{grow, grow_fn, grow_set} to methods.
Remove vec::{map, mapi, zip_map} and the methods, except for .map, since this
is very common, and the replacement (.iter().transform().collect()) is very
ugly.
auto merge of #7487 : huonw/rust/vec-kill, r=cmr

Continuation of #7430.

I haven't removed the `map` method, since the replacement `v.iter().transform(f).collect::<~[SomeType]>()` is a little ridiculous at the moment.