Make Remote-Base-Directory functional for server

Properly uses the Remote-Base-Directory to set the target
location for files on the FTP backend, e.g. if you set
`Remote-Base-Directory=gravwell`, your uploaded shards will
go to `/home/<username>/gravwell/` instead of just `/home/<username>/`

Addresses #6

server/server.go

@@ -67,6 +67,7 @@ func main() {
 		fcfg := ftpstore.FtpStoreConfig{
 			LocalStore: cfg.Global.Storage_Directory,
 			FtpServer:  cfg.Global.FTP_Server,
+			BaseDir:    cfg.Global.Remote_Base_Directory,
 			Username:   cfg.Global.FTP_Username,
 			Password:   cfg.Global.FTP_Password,
 			Lgr:        lgr,