added Guest Checkout, check for signature at notification and redirect, send signature, timestamp, and order id instead of secret in helper, update parameter names
Guest Checkout now always enabled

Letting merchant choose whether or not to enable GC by setting
:credential4 to "true" just didn't seem correct, so I just force GC to
be enabled always
standardize amount param
actually, no need
Add credit to dwolla integration files
remove header comments
centralize the signature verification method
rename credentials params
update tests to reflect the change in credential parameter names
remote comment headers, fix credential var names, fix sig verify fn
Authorize.Net: Better match eCheck.Net reqs

This better complies with the eCheck.Net request spec, including adding
the bank name as a field.
Updated the bluepay module to support the bp20post api; fixed broken bluepay specs
fixing bluepay compatability with ruby 1.8.7
Deprecate credit method in net registry gateway
Merge pull request #702 from jduff/deprectate_credit_net_registry

Deprecate credit method in net registry gateway
Don't include customer_number unless it is numeric.
Don't include customer id unless it is numeric.
Accept numeric strings as well.
Epay: Deprecate credit method
Moved parser-gateway sanity check to tests; uncommented check test; other small style/factor changes per discussion on pull req