Add Perdurant as parent of Event and Action

Perdurant was originally proposed in Issue 544 with a sibling class.
Issue 651 introduces Perdurant independently due to timelining needs.

No effects were observed on Make-managed files.

References:
* #544
* #651

Signed-off-by: Alex Nelson <alexander.nelson@nist.gov>

Author: ajnelson-nist

ontology/uco/action/action.ttl

@@ -37,7 +37,7 @@ action:Action
 		owl:Class ,
 		sh:NodeShape
 		;
-	rdfs:subClassOf core:UcoObject ;
+	rdfs:subClassOf core:Perdurant ;
 	rdfs:label "Action"@en ;
 	rdfs:comment "An action is something that may be done or performed."@en ;
 	owl:disjointWith core:Event ;

ontology/uco/core/core.ttl

@@ -181,7 +181,7 @@ core:Event
 		owl:Class ,
 		sh:NodeShape
 		;
-	rdfs:subClassOf core:UcoObject ;
+	rdfs:subClassOf core:Perdurant ;
 	rdfs:label "Event"@en ;
 	rdfs:comment "An Event is a noteworthy occurrence (something that happens or might happen)."@en ;
 	owl:disjointWith action:Action ;
@@ -330,6 +330,17 @@ core:ObjectStatusVocab
 	] ;
 	.
 
+core:Perdurant
+	a owl:Class ;
+	rdfs:subClassOf core:UcoObject ;
+	rdfs:label "Perdurant"@en ;
+	rdfs:comment "Perdurants \"are individuals composed of temporal parts,\" or the start or end of such an individual.  \"They happen in time in the sense that they extend in time accumulating temporal parts.\"  In any instant where a non-instantaneous perdurant exists, \"it is not the case that all its temporal parts are present.\"  Also known as \"Occurrents\" in some models [e.g., BFO concept 3].  [Definition quoted and adapted from Section 2 of Guizzardi et al., \"Towards Ontological Foundations for the Conceptual Modeling of Events,\" 2013; and, the BFO-2020 definition of \"occurrent\".]  Taking for example a human: the human *is not* a perdurant; but, the human's life *is* a perdurant.  Taking for example a computer process, as in the operating system object in which a piece of software is executed: The process *is not* a perdurant, because if time is frozen such as in a virtual machine snapshot, everything about the process exists; but, the process's execution taking place *is* a perdurant, as is the instant in which the process terminates."@en ;
+	rdfs:seeAlso
+		<http://purl.obolibrary.org/obo/BFO_0000003> ,
+		<https://doi.org/10.1007/978-3-642-41924-9_27>
+		;
+	.
+
 core:Relationship
 	a
 		owl:Class ,