Log Message:
Update ruby-activerecord31 to 3.1.6.

pkgsrc change: add RUBY_RAILS_STRICT_DEP which will be enabled later.

## Rails 3.1.6 (Jun 12, 2012)

*   protect against the nesting of hashes changing the
    table context in the next call to build_from_hash. This fix
    covers this case as well.

    CVE-2012-2695