Add aerospike plugin support

- Does not use the aerospike client, but sends the stats command
  using the aerospike required format
- Queries available namespaces and gets stats for all of them

closes #300

plugins/all/all.go

@@ -1,6 +1,7 @@
 package all
 
 import (
+	_ "github.com/influxdb/telegraf/plugins/aerospike"
 	_ "github.com/influxdb/telegraf/plugins/apache"
 	_ "github.com/influxdb/telegraf/plugins/bcache"
 	_ "github.com/influxdb/telegraf/plugins/disque"