Adding Spring XML namespace support for COMOT API

[olmoser]

allow configuration of COMOT's ToscaDescriptionBuilder and SalsaClient via a dedicated Spring XML namespace such as:

<comot:tosca-description-builder validating="true"  
  artifact-type-namespace="http://void.org" 
  artifact-type-prefix="salsa" />

and for SalsaClient:

<comot:salsa-client host="localhost" port="9090">
  <comot:salsa-client-configuration base-uri="/salsa-dev" .../>
</comot:salsa-client>