HTCondorWiki: Dag Man Design Docs

 Here are the areas that should be documented (see gittrac #2815).  I re-ordered them somewhat to make the list more logical in terms of related functionality.
 
-*: {wiki: HtcondorSubmitDag Condor_submit_dag/scheduler universe startup}
+*: {wiki: CondorSubmitDag Condor_submit_dag/scheduler universe startup}
 *: {wiki: DagFileParsing DAG file parsing}
 *: {wiki: RescueDag Rescue DAG/condor_rm of DAGMan}
 *: {wiki: DagRecovery Recovery mode/condor_hold/condor_release}