Fixes rust-lang#24030

Of the four code samples with modules in TRPL:

    - 2 use `mod test`
    - 2 use `mod tests`

We should be consistent here, but which is right? The stdlib is split:

    $ grep -r 'mod tests {' src/lib* | wc -l
          63
    $ grep -r 'mod test {'  src/lib* | wc -l
          58

Subjectively, I like the plural, but both the language reference and the
style guide recommend the singular. So we'll go with that here, for now.

traits.md said:

If we add a `use` line right above `main` and make the right things public,
everything is fine:

However, the use line was actually placed at the top of the file instead.  Move
the use line to right above main.  That also makes the example more evocative
of cases where the module is defined in a separate file.

There is no `read_string` function, and `lines` never returns an error.

@mahkoh points out in rust-lang#15628 that unicode.py does not use
normative data for Grapheme classes. This pr fixes that issue.

In addition, GC_RegionalIndicator is renamed GC_Regional_Indicator
in order to stay in line with the Unicode class name definitions.
I have updated refs in u_str.rs, and verified that there are no
refs elsewhere in the codebase. However, in principle someone
using the unicode tables for their own purposes might see breakage
from this.

Use HTTPS where possible to avoid plaintext HTTP connections.

Closes rust-lang#22560

People use programming language *implementations* like Ruby MRI, CPython, and SpiderMonkey for executing programs.

 cc @steveklabnik

 Fixes rust-lang#24030

Of the four code samples with modules in TRPL:

    - 2 use `mod test`
    - 2 use `mod tests`

We should be consistent here, but which is right? The stdlib is split:

    $ grep -r 'mod tests {' src/lib* | wc -l
          63
    $ grep -r 'mod test {'  src/lib* | wc -l
          58

Subjectively, I like the plural, but both the language reference and the
style guide recommend the singular. So we'll go with that here, for now.

r? @steveklabnik

…d-error, r=huon

…a-docs, r=huon

 This probably needs a bit more work, but I wanted to try and capture some common use cases and be a bit more helpful.

r? @huonw
cc @steveklabnik

 Fixes rust-lang#24060.

 traits.md said:

If we add a `use` line right above `main` and make the right things public,
everything is fine:

However, the use line was actually placed at the top of the file instead.  Move
the use line to right above main.  That also makes the example more evocative
of cases where the module is defined in a separate file.

 * Fix broken \"module-level documentation\" link on the [`trait Any` docs](http://doc.rust-lang.org/std/any/trait.Any.html) and related broken markup on the [`std::any` docs](http://doc.rust-lang.org/std/any/index.html).

* Remove an outdated or incorrect notice in the `BufRead::lines` docs. There is no such `read_string` function, and `lines` never returns an error.

r? @steveklabnik

@mahkoh points out in rust-lang#15628 that unicode.py does not use
normative data for Grapheme classes. This pr fixes that issue,
and does some minor cleanup of the unicode.py script.

In addition, GC_RegionalIndicator is renamed GC_Regional_Indicator
in order to stay in line with the Unicode class name definitions.
I have updated refs in u_str.rs, and verified that there are no
refs elsewhere in the codebase. However, in principle someone
using the unicode tables for their own purposes might see breakage
from this.

Use HTTPS where possible to avoid plaintext HTTP connections.

Closes rust-lang#22560

People use programming language *implementations* like Ruby MRI, CPython, and SpiderMonkey for executing programs.

This fix allows the gdb debuginfo tests to pass on FreeBSD when using the newer 7.8 package.