(portage-#41) Default package_* to present

Previously if the ensure value was not specified and no other properties
or parameters were given, package_* entries would be treated as
unmanaged. This commit defaults the ensure to present for all package_
types.
Merge branch '2.x-issue_41-default-present' into 2.x
Clean up rspec spec_helper inclusion
Update specs to use rspec described_class
Clean up type specs to use rspec described_class helper
Merge branch 'master-cleanup-specs'
Merge branch 'master' into 2.x
(maint) Fix parent provider for package_mask
Merge branch 'master' into 2.x
Initial implementation of integration coverage
Initial approach for fixture helpers
Basic spec for package_mask integration tests