Add Citrus gateway
Citrus: Get the integration into working condition and clean up the code.
Add PayuPaisa gateway
Add Be2bill gateway

http://www.be2bill.com/

Closes #747.
Be2Bill: Use #include? instead of #in?
Spreedly: Add ability to retain on success

We now support the ability to pass an optional parameter to the purchase
and authorize calls to notify Spreedly to store (retain) the card if the
purchase/authorize succeeds.

Closes #860.
Merge pull request #857 from Shopify/viatechs-master

Add Citrus integration
Merge pull request #858 from Shopify/payu_paisa

Add PayuPaisa gateway
initial setup
add notification
Spreedly: Pass verification value

Closes #861.
Disambiguate PayuIn[Paisa] test suite names
ACK function should accept a token for verification
acknowledge method should receive an authcode that it can choose to ignore
During the certification process, found out that CurrencyCode and
CurrencyExponent were not being set while performing transactions with saved
profiles.  This commit fixes that.
tests for orbital_mandatory_field_fix ee1a3ff
i missed a syntax error...
Paymill: Add support for specifying the :customer

Closes #749
Realex: Correct AVS input format

Closes #754.
USAEpay Transaction: Use sandbox when in test mode

When the USAEPay transaction gateway is set to "test", it should use the
Sandbox. The Advanced gateway was already configured to do this, but the
Transaction gateway was overlooked.

Closes #757.