Adding a new optional variable called trans_id_suffix

The trans_id_suffix (default is empty) would be appended to the swift transaction
id allowing one to easily figure out from which cluster that X-Trans-Id
belongs to. This is very useful when one is managing more than one swift
cluster. Also updated sample and manpage to reflect the changes.

Change-Id: Icdf63643e9c1bde36a9ef5e3f41ee9fb20e55f5d
Merge "Adding a new optional variable called trans_id_suffix"