provisioner/shell: fix provisioner to use UnixReader [GH-477]

Packer was using the original file reader when uploading, instead of the UnixReader /cc @mitchellh
Update CHANGELOG
Fix UnixReader panic on empty lines.

Added a test for the failure.

Most of the scanner code looks like it's a modified version of
bufio.ScanLines, so I changed it to use that but always add a line feed.
Fix the way we run commands in chroot.

* Single quotes around chroot command cause it to fail.
* The chroot command also gets passed through the CommandWrapper template, so having sudo would clash with however the user wants to run it.
* Fix spelling mistake.
add environments_path and chef_environment support to chef provisioner
formatting
Updated web site doc. for avail commands list
Merge pull request #486 from tchaudhri/update_site_avail_commands_list

website: Updated web site doc. for avail commands list
Merge pull request #483 from netshade/chef-environment-support

provisioner/chef-solo: chef environment support
Update CHANGELOG
provisioner/chef-solo: alphabetize tests and such

/cc @netshade
provisioner/chef-solo: unused var
v0.3.9
Up version for dev
An SSH timeout should be treated as an error
Merge pull request #491 from patricklucas/ssh_timeout_should_be_error

common: An SSH timeout should be treated as an error
Update CHANGELOG
builder/virtualbox: error if version can't be detected [GH-488]
builder/virtualbox: detect vboxdrv issues [GH-488]