Several additions

1) OcsScriptMapper - Set the foreign-source name on the requisition when
processing the SNMP Devices through an external script

2) Create two methods on IpInterfaceHelper:

 a) selectIpAddressWhiteAndBlackOnly - returns the IP of the SNMP
    device only if the IP is on the whiteList and not on the
    blackList, otherwise return null
 b) selectIpAddress - returns the IP of the SNMP device only if it is
    not on the blackList (relaxed method), otherwhise return null

3) OcsDefaultMapper - Use selectIpAddressWhiteAndBlackOnly() then
processing SNMP devices.