Fixed str::raw::push_byte

It was previously pushing the byte on top of the string's null
terminator. I added a test to make sure it doesn't break in the future.
fix warning still mentioning the `again` keyword
Implemented iterator for TrieMap

Closes #5506.
Remove debug printing.
Open files in binary mode. Closes #3948
Add extra::arena::Arena::new{, _with_size}.

Signed-off-by: OGINO Masanori <masanori.ogino@gmail.com>
auto merge of #8183 : omasanori/rust/migrate-new, r=sanxiyn

It seems that relatively new code uses `Foo::new()` instead of `Foo()` so I wrote a patch to migrate some structs to the former style.
Is it a right direction? If there are any guidelines not to use new()-style, could you add them to the [style guide](https://github.com/omasanori/rust/wiki/Note-style-guide)?
auto merge of #8289 : sfackler/rust/push_byte, r=erickt

It was previously pushing the byte on top of the string's null
terminator. I added a test to make sure it doesn't break in the future.
auto merge of #8292 : thestinger/rust/fix_loop_warning, r=brson
auto merge of #8293 : dim-an/rust/trie-iterator, r=thestinger

Closes #5506.
auto merge of #8298 : darkf/rust/fix-3948, r=pcwalton
std: Add .consume_iter() for Option, to make it reusable

Let Option be a base for a widely useful one- or zero- item iterator.
Refactor OptionIterator to support any generic element type, so the same
iterator impl can be used for both &T, &mut T and T iterators.
std: Convert Result to use external iterators

convert iter() and iter_err() for Result. Use OptionIterator.
std: Remove unused trait bound in Result::map
std: Implement RandomAccessIterator for Invert
std: Improve vec::ChunkIter

Implement clone, bidirectionality and random access for this iterator
std: Add iterator::Repeat to repeat an element endlessly
std: Rewrite the HashSet set operation iterators

Use the Repeat iterator to carry the "explicit closure capture" that was
previously done with the custom EnvFilterIterator.
std: Use method name Option::consume

With Option as the simplest container, `consume` is the way to turn it
into a by-value iterator.
std: Improve the documentation for iterator::Invert