this is reaching ruby 1.8.7-levels of pissing me off

Signed-off-by: Lamont Granquist <lamont@scriptkiddie.org>

Signed-off-by: Lamont Granquist <lamont@scriptkiddie.org>

* Always use `*_proxy` environment variables.
* Make a `ChefConfig::Config.proxy_uri` method that gets used by
  `Chef::Provider::RemoteFile::FTP` and `Chef::HTTP::BasicClient`.
* Remove `env` method from `Chef::HTTP::BasicClient` (using
  `stub_const("ENV", ...)` in specs instead.)
* Remove `http_proxy_user` and `http_proxy_pass` methods from
  `Chef::HTTP::BasicClient` (replaced by functionality in `ChefConfig`.)

252  Style/TrailingCommaInLiteral
84   Style/TrailingCommaInArguments
15   Style/SpaceAroundKeyword
--
351  Total

We already dealt with SpaceAroundKeyword under its old name
SpaceBeforeModifierKeyword, it looks like it got stricter about
spaces after keywords.

TrailingComma also got split, and it looks like the
TrailingCommaInArguments behavior is new?

This is an entirely mechanically generated (chefstyle -a) change, to go
along with chef/chefstyle#5 . We should pick something and use it
consistently, and my opinion is that double quotes are the appropriate
thing.

chefstyle -a fixed 1044 occurrances

This change adds support to Chef's core http libs to
honor a proxy uri set in the environment not just
chef/knife config. It also adds support for username
and password both in uri and env.

The order of precidence for values is uri, config, env.