update data types for params so null can be passed ref #614
routing table updates

added methods to better abstract listings of routing tables Ref #622 -
these methods allow the listing of "non-main" route tables, use
"getRoutingTableForSubnet" for the main table for a subnet, use new
methods "listRoutingTablesForSubnet" for a list of all routetables for
a subnet [Ref #641]
Added AssociationId for being able to detach in vlan situations (newever version of IP coverage)

Ref #614
Merge pull request #10 from TheWeatherCompany/06_10_2013

06 10 2013