Added stricter resource collection arg validation.

[trevorrowe]

Resource has many operation accept a hash argument only. Updated collection methods to now raise on argument errors.

bucket = Aws::S3::Bucket.new('bucket-name')

bucket.objects('key')
#=> now raises ArgumentError, expecting Hash, got String

bucket.objects(1,2,3)
#=> now raises ArgumentError, expecting 0..1 args, got 2

[awood45]

Sanity Check: Is there any collection, anywhere, that behaves differently? Are we going to be able to ensure that all collections going forward behave in this manner?

[awood45]

Change itself looks fine w/r/t stated intent.

[trevorrowe]

All resource collection / has many associations are wrappers around paginated API calls. The only accepted arguments are :limit and pass-through arguments to the client operation. This is strictly always a hash. This is per the resources spec.