doc: use backticks for code-in-comments.
auto merge of #11996 : lecram/rust/master, r=pcwalton

This Pull Request aims to add backticks to all instances of code inside comments in snippets present in tutorial.md. It also includes backticks for filenames in the same conditions. See #11796 for motivation.
libnative: fix epoll_event struct layout

Make the definition of epoll_event use natural alignment on all
architectures except x86_64.

Before this commit, the struct was always 12 bytes big, which works okay
on x86 and x86_64 but not on ARM and MIPS, where it should be 16 bytes
big with the `data` field aligned on an 8 byte boundary.
Move doc/ to src/doc/

We generate documentation into the doc/ directory, so we shouldn't be
intermingling source files with generated files
Remove VPATH usage in Makefiles

This is just messing up all the doc dependencies because of such similar
directory names and file names.

Closes #11422
Rewrite the doc makefile for doc => src/doc

This continues to generate all documentation into doc, but it now looks for
source files in src/doc

Closes #11860
Closes #11970
auto merge of #11891 : alexcrichton/rust/docs, r=brson

I moved all documentation sources (guides, manuals, etc) to `src/doc` to free up `doc` as a build directory for all generated files.

At the same time, I also removed our usage of `VPATH` from the makefiles because it was wreaking havoc with doc deps and it's not very necessary now that we're primarily a rust project rather than having a good portion of C++/C inside of it.
Update po4a.conf and regenerate .po files.

Also, I've corrected src/doc/README.md in line with this change.

Signed-off-by: OGINO Masanori <masanori.ogino@gmail.com>
Move term, terminfo out of extra.

cc #8784
auto merge of #11945 : xales/rust/libextra, r=huonw

cc #8784
auto merge of #12005 : omasanori/rust/update-trans, r=brson

Also, I've corrected src/doc/README.md in line with this change.
auto merge of #12003 : bnoordhuis/rust/sizeof-epoll-event-fixup, r=brson

Make the definition of epoll_event use natural alignment on all
architectures except x86_64.

Before this commit, the struct was always 12 bytes big, which works okay
on x86 and x86_64 but not on ARM and MIPS, where it should be 16 bytes
big with the `data` field aligned on an 8 byte boundary.
Remove unnecessary trailing commas.
auto merge of #12013 : Hywan/rust/doc, r=sanxiyn
std: Remove io::io_error

* All I/O now returns IoResult<T> = Result<T, IoError>
* All formatting traits now return fmt::Result = IoResult<()>
* The if_ok!() macro was added to libstd
extra: Remove io_error usage
syntax: Remove io_error usage
rustc: Remove io_error usage
compiletest: Remove io_error usage
glob: Remove io_error usage