Merge rbenv master

Forwarded from https://github.com/pyenv/pyenv/pull/606.

Conflicts:
	README.md
	libexec/pyenv---version
	libexec/pyenv-init
	libexec/rbenv
	libexec/rbenv-sh-shell
	libexec/rbenv-which
	test/init.bats
	test/shell.bats

Add micropython-dev

Prefer 'set' over 'setenv' for fish shell

Make homebrew installation instructions more clear

Revert back to original quoting style used before previous commit.
Adjust init.bats to reflect changes for successful tests.

I work on a team that has followed the Homebrew installations. More than once we've missed the `rbenv init` instruction and it has caused headaches down the road. This formatting makes it harder to miss.

Fix --enable-shared sample command

Fixes pip-rehash to rehash if pip was called with a flag

`pip -v install foobar` or `pip -q install foobar` did not trigger a rehash before. Now it should have the same behaviour as `pip install foobar`.

Update link to pyenv shell documentation in README

add -f to anaconda install script

Remove duplicate heading

Link was pointing to this heading. It seemed incorrect

Add miniconda3-4.2.12 and miniconda3-4.3.11

replace github.com/yyuu with github.com/pyenv

The setenv function in fish shell has changed dramatically in
75600b6b53
It now conforms to the csh version, which takes at most two arguments.
In this init script, the form
    setenv PATH prepend_something $PATH
had been used, which had too many arguments.
Since setenv isn't a native command in fish, a suitable replacement is
to use the "set -gx" command, which can consume multiple arguments.

This prevents CDPATH from becoming an issue.

Closes #866.

closes #888

Workaround for CI failures with versions with multiple digits

https://travis-ci.org/pyenv/pyenv/jobs/215777826

Update miniconda-latest and miniconda3-latest

- some versions of bash (e.g. 4.3.11) complain about clobbering
  /dev/null, use bash's explicit >| operator to ignore noclober
- not sure if the original #759 report has the same cause
- https://github.com/rbenv/rbenv/issues/759#issuecomment-289326891

python-build: Fix typo in MacOS packages for anaconda2-4.3.0/4.2.0

The package names in the python-build files for anaconda2-4.2.0 and
anaconda2-4.3.0 both had 'Anaconda2-4.2.1-MacOSX-x86_64' erroneously
listed as the package name. Anaconda2-4.2.1 is not a version of Anaconda
in existence. The URL arguments were correct, just not the package name
arguments.

python-build: Add Anaconda2/Anaconda3 4.3.1

* Update version to 1.0.9