Add insert_at to resource_collection
Modify wording in exception
add CHANGELOG for pr#1395
Merge pull request #1873 from opscode/lcg/insert_at

Lcg/insert at
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
Merge pull request #1883 from opscode/lcg/1561

Lcg/1561
Bump version to 12.0.0 alpha 1