try to convert to array else return empty array
add hash option to spree preferences
use wrap instead of try
spec for array preference
convert strings and arrays to hash in hash preference
an empty array is already returned from #wrap
arrays should be of an even count when converting to hash
it should raise an argument error when the count is odd
remove extra line endings
store hash with keys that are integers
add action controller parameters to the mix
return value if class is an ancestor of the hash class