Enable email notifications from Travis CI

http://docs.travis-ci.com/user/notifications/
> By default, email notifications will be sent to the committer and the commit author, if they are members of the repository (that is, they have push or admin permissions for public repositories, or if they have pull, push or admin permissions for private repositories).
>
> And it will by default send emails when, on the given branch:
>
> * a build was just broken or still is broken
> * a previously broken build was just fixed
Return a Temporary from *Binding::Wrap.

Returning a JS<T> is GC-unsafe.

This commit also includes some cleanup around Node and Document reflection.
Include some jemalloc stats in the -m measurements.
Enable rust-phf build and bump rust-phf submodule ptr.
Merge pull request #2804 from glennw/enable-phf

Enable rust-phf build and bump rust-phf submodule ptr.
Correct the allowed MPL licenses in licenseck.
Remove a glob import from tidy.py.
Remove unused code from tidy.py.
Stop using fileinput in tidy.py.

The code is expressed much more clearly with a loop over the files instead.
Fix PEP8 violations in tidy.py.
Test for trailing spaces in tidy.py.
Test for missing newlines at end of file in tidy.py.
Test for tabs in tidy.py.
Test for carriage returns in tidy.py.
Run tidy.py on Travis.
Merge pull request #2806 from Ms2ger/tidy

Improve and extend tidy.py, and run it on Travis.
Remove some dead code and fix some pyflakes warnings in CodegenRust.py.
adding 2 new default arguments when running make check-wpt so that it does not fail saying KeyError: 'debug_args' or KeyError: 'interactive'
Update run.py

None and False are better values here (thanks to @jgraham).
Merge pull request #2801 from Ms2ger/wrap-temp

Return a Temporary from *Binding::Wrap.