Additional attributes "previous_state", "node_type", "title", "seq_no" for jobChain-Nodes

Additional attributes "previous_state", "node_type", "title", "seq_no" for jobChain-Nodes.

TODO:
Add the following optional attributes to job_chain_node in scheduler.xsd:
<xsd:attribute name="previous_state" type="String"/>
<xsd:attribute name="node_type" type="xsd:nonNegativeInteger"/>
<xsd:attribute name="title" type="String"/>
<xsd:attribute name="seq_no" type="xsd:nonNegativeInteger"/>

node_type: representing Error, Job, Splitter, synch, eventtrigger, ...