add 'class Chef' outer scope

clearly we need a rubocop rule for this.

this fixes this exception which we were throwing incorrectly:

[2014-10-28T02:57:54+00:00] FATAL: NameError: uninitialized constant
Chef::Application::Exceptions

using 'class Chef::Application' saves a tiny amount of typing and
indentation but does not open up the outer lexical scope and breaks
otherwise working code like this.
windows_package installer_type should be a symbol

Fixes #1997
Update CHANGELOG for #1997/#2220
Merge pull request #2308 from opscode/lcg/fix-exceptions

Chef::Application outer lexical scope
Make sure windows_service and windows_package resources are found with the new dynamic provider resolver.
Make sure the event log related capability is turned off on Windows 2003 boxes since it's not supported.
Disable eventlogger on win2k3
Turn off the alternative resource name tests for windows service andpackage.
Fix freebsd group provider regression introduced by b06510323102fcb35fb7b02891591b3a540ddf27 when there is no members while creating the group.
Fix the logic that checks for existing reboot pending in reboot pending tests.
Updates based on the PR comments.
add 14.04 to supported vagrant distros

10.04 and 14.10 'documented' as broken in the upstream
mysql cookbook
Merge pull request #2315 from opscode/lcg/more-vagrant

add 14.04 to supported vagrant distros
disable workstation tests for aix.
Merge pull request #2320 from ClogenyTechnologies/kd-aix-fixes-wrktn

Disable workstation tests for aix.
Fixing documentation error
Fix the after blocks in reboot_pending specs.
Updating travis to run builds on 12-stable
Merge pull request #2313 from opscode/sersut/win-res-lookup-fix

Make sure windows_service and windows_package resources are found with the new dynamic provider resolver.
Merge pull request #2322 from opscode/tball/doc-fix

Fixing documentation error (leftovers, no longer correct)