Create civicrm_payment_token table and api & add token_id field to recurring table

Proposed field spec is -

<?xml version="1.0" encoding="iso-8859-1" ?>

<table>
<base>CRM/Financial</base>
<class>PaymentToken</class>
<name>civicrm_payment_token</name>
<comment>Payment Token</comment>
<add>4.7</add>
<field>
<name>id</name>
<type>int unsigned</type>
<required>true</required>
<comment>Payment Token ID</comment>
<add>4.7</add>
</field>
<primaryKey>
<name>id</name>
<autoincrement>true</autoincrement>
</primaryKey>
<field>
<name>contact_id</name>
<title>Contact ID</title>
<type>int unsigned</type>
<required>true</required>
<comment>FK to Contact ID for the owner of the token</comment>
<add>4.7</add>
</field>
<foreignKey>
<name>contact_id</name>
<table>civicrm_contact</table>
<key>id</key>
<add>4.7</add>
<onDelete>CASCADE</onDelete>
</foreignKey>
<field>
<name>payment_processor_id</name>
<title>Payment Processor ID</title>
<type>int unsigned</type>
<required>true</required>
<comment></comment>
<add>4.7</add>
</field>
<foreignKey>
<name>payment_processor_id</name>
<table>civicrm_payment_processor</table>
<key>id</key>
<add>4.7</add>
<onDelete>RESTRICT</onDelete>
</foreignKey>
<field>
<name>token</name>
<type>varchar</type>
<length>255</length>
<required>true</required>
<comment>Externally provided token string</comment>
<add>4.7</add>
</field>
<field>
<name>created_date</name>
<type>timestamp</type>
<comment>Date created</comment>
<add>4.7</add>
</field>
<field>
<name>created_id</name>
<type>int unsigned</type>
<length>255</length>
<comment>Contact ID of token creator</comment>
<add>4.7</add>
</field>
<field>
<name>expiry_date</name>
<type>datetime</type>
<comment>Date this token expires</comment>
<add>4.7</add>
</field>
<field>
<name>email</name>
<length>255</length>
<type>varchar</type>
<comment>Email at the time of token creation. Useful for fraud forensics</comment>
<add>4.7</add>
</field>
<field>
<name>billing_first_name</name>
<type>string</type>
<length>255</length>
<comment>Billing first name at the time of token creation. Useful for fraud forensics</comment>
<add>4.7</add>
</field>
<field>
<name>billing_middle_name</name>
<type>string</type>
<length>255</length>
<comment>Billing middle name at the time of token creation. Useful for fraud forensics</comment>
<add>4.7</add>
</field>
<field>
<name>billing_last_name</name>
<type>string</type>
<length>255</length>
<comment>Billing last name at the time of token creation. Useful for fraud forensics</comment>
<add>4.7</add>
</field>
<field>
<name>account_number</name>
<type>varchar</type>
<length>255</length>
<comment>Holds the part of the card number or account details that may be retained or displayed</comment>
<add>4.7</add>
</field>
<field>
<name>ip_address</name>
<type>varchar</type>
<length>255</length>
<comment>IP used when creating the token. Useful for fraud forensics</comment>
<add>4.7</add>
</field>
</table>

Note that the following need to be updated

Create sql script - let's do a CREATE TABLE IF NOT EXISTS - so people can do this via extension until 4.7
Update script
XML schema file