Fix that #pluck wasn't rescuing ThrowResult, meaning it would blow up when failing to construct_limited_ids_condition.
Add coverage for the fact that pluck without an argument returns all the table's columns.
No point in memoizing a simple literal string.
Make NullRelation a bit more like a real relation by returning 0 for #calculate(:count)
Rather than raising ThrowResult when construct_limited_ids_conditions comes up empty, set the relation to NullRelation and rely on its results.

This will help avoid errors like 2fcafee250ee2, because in most cases NullRelation will do the right thing. Minor bonus is avoiding the use of exceptions for flow control.
Update filter_parameters related docs, as they have been moved to initializers.
Update configuration docs for assets.enabled, as it's set true by default in the configuration and doesn't appear in the config files anymore.
update_counters accepts a hash, not an array of hashes
Documentation: Notifications queue does not run in a thread.
In rails 4 there are much more ways to retrieve a single object
Added an example for primary_key option
enhanced comments for foreign_key_present? method
correction on cache.fetch race_condition_ttl
Merge pull request #138 from lifo/cache

correction on cache.fetch race_condition_ttl
Add note about upgrading custom routes from `put` to `patch`.
Correct the assertion that join table columns have no options, mind context.
removes forgotten avatar
minor comments cleanup
Fixed quotes in environment example in Rails Application Templates guide.
End-of-line whitespace hunt