ST6RI-844 Fixes for minor build issues

 - Projects were updated to explicitly specify UTF-8 character encoding
 - Some redundant configuration was removed from Maven
 - A deprecated field usage was updated
 - Unused (and deprecated) UpdateSiteNature was removed from site project

Author: ujhelyiz

org.omg.sysml.jupyter.jupyterlab/pom.xml

@@ -126,7 +126,6 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-clean-plugin</artifactId>
-        <version>${maven-clean-plugin.version}</version>
         <configuration>
           <filesets>
             <fileset>

org.omg.sysml.plantuml.eclipse/.settings/org.eclipse.core.resources.prefs

@@ -0,0 +1,2 @@
+eclipse.preferences.version=1
+encoding/<project>=UTF-8

org.omg.sysml.plantuml.feature/.settings/org.eclipse.core.resources.prefs

@@ -0,0 +1,2 @@
+eclipse.preferences.version=1
+encoding/<project>=UTF-8

org.omg.sysml.plantuml/.settings/org.eclipse.core.resources.prefs

@@ -0,0 +1,2 @@
+eclipse.preferences.version=1
+encoding/<project>=UTF-8

org.omg.sysml.site/.project

@@ -4,14 +4,4 @@
 	<comment></comment>
 	<projects>
 	</projects>
-	<buildSpec>
-		<buildCommand>
-			<name>org.eclipse.pde.UpdateSiteBuilder</name>
-			<arguments>
-			</arguments>
-		</buildCommand>
-	</buildSpec>
-	<natures>
-		<nature>org.eclipse.pde.UpdateSiteNature</nature>
-	</natures>
 </projectDescription>

org.omg.sysml.site/.settings/org.eclipse.core.resources.prefs

@@ -0,0 +1,2 @@
+eclipse.preferences.version=1
+encoding/<project>=UTF-8

org.omg.sysml.uml.ecore.importer/.settings/org.eclipse.core.resources.prefs

@@ -0,0 +1,2 @@
+eclipse.preferences.version=1
+encoding/<project>=UTF-8

org.omg.sysml.xtext/src/org/omg/sysml/xtext/InternalParserSplitterFragment.java

@@ -24,6 +24,7 @@
 package org.omg.sysml.xtext;
 
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
@@ -33,8 +34,6 @@
 import org.apache.log4j.Logger;
 import org.eclipse.xtext.xtext.generator.AbstractXtextGeneratorFragment;
 
-import com.google.common.base.Charsets;
-
 public class InternalParserSplitterFragment extends AbstractXtextGeneratorFragment {
 
 	private final static Logger LOGGER = Logger.getLogger(InternalParserSplitterFragment.class);
@@ -162,7 +161,7 @@ public void readInput() {
 		String inputPath = inputDirectory + "/" + originalClassName + ".java";
 		LOGGER.info("Reading " + inputPath);
 		try {
-			content = Files.readString(Paths.get(inputPath), Charsets.UTF_8);
+			content = Files.readString(Paths.get(inputPath), StandardCharsets.UTF_8);
 		} catch (Exception e) {
 			LOGGER.error(e);
 		}
@@ -178,7 +177,7 @@ protected void writeOutput(String fileName, String output) throws IOException {
 		LOGGER.info("Writing " + outputPath);
 		Path outputFile = Paths.get(outputPath);
 		try {
-			Files.writeString(outputFile, output, Charsets.UTF_8);
+			Files.writeString(outputFile, output, StandardCharsets.UTF_8);
 		} catch (Exception e) {
 			LOGGER.error(e);
 			throw e;