add_env_to_scm_resource
fix: remove oldline and check avail.
set nil by default, add two specs
HOME can overwrite by user with OVERRIDE_HOME
cleanup: remove OVERRIDE_HOME
add md files for PR #1561
initial pass at supporting version constraints in value_for_platform
use Chef::VersionConstraint, not Gem in value_for_platform
add tests for pessmisitics to value_for_platform
update comment for value_for_platform
raise error if multiple constraints are met
use raise, not fail
add value_for_platform to DOC_CHANGES.md
add md files for pr#1726
Merge pull request #1883 from opscode/lcg/1561

Lcg/1561
CHEF-1737: Fix noauto support.
Add fsck device support.
Allow vxfs device types.
CHEF-1737: New provider rspec tests
CHEF-1737: Remove extraneous notes.
Fix review call outs.
Add support for remount options - See #1782
CHEF-1737: Minor clean up.