add a strategy for applying conditions to MiqQueue

This commit accomplishes 2 things:

1. Removes sanitize_sql_for_conditions
2. Updates finder syntax to work with Rails 4

sanitize_sql_for_conditions is deprecated, so we need to stop using it.
This commit introduces a lambda as a strategy for applying where
conditions to the query.  This lets us keep the hash conditionals, but
optionally apply a "yaml conditional" as a string.  Since we can call
`where` twice, there is no need for sanitize_sql_for_conditions.
I'm not sure I understand the need for the lamdba since the caller only uses MiqQueue (which is self).  Can this be simplified to just use AR:Relation chaining to avoid the lambda (and thus the binding?).  Something like:

```ruby
add_where = if conds.key?(:args)
              args = YAML.dump(conds.delete(:args))
              where(conds).where('args = ?', args)
            else
              where(conds)
            end
```

Then down below

```ruby
add_where.order("priority, id")...
```