ssrclient: return list of floats instead of individual floats

With this, only one IP packet per message should be generated.
This is no guarantee, though.

Also, now it is compatible with both iemnet/tcpclient and
mrpeach/tcpclient.
ssrclient: allow 1/0 in addition to true/false

According to the xs:boolean data type.
http://www.w3.org/TR/xmlschema-2/#boolean
ssrclient: avoid variable for SLAXML library