[New] Changed Parameter.getValue() for implicit cast to type

Now you can simplify:
StringParameter valueS = resource.getParameter("bagId", "paramId");
String value = valueS.getValue();

to:
String value = resource.getParameter("bagId", "paramId").getValue();

Casting is done implicitly, thus this can lead to runtime exceptions
when the parameter is not of the relevant type, but otherwise it reduces
the code by one line.

Setting the value in this manor is not supported due to the
ListParameters requiring a type of List<T>.

li.strolch.model/src/main/java/li/strolch/model/parameter/BooleanParameter.java

@@ -53,6 +53,7 @@ public class BooleanParameter extends AbstractParameter<Boolean> {
 		return this.value.toString();
 	}
 
+	@SuppressWarnings("unchecked")
 	@Override
 	public Boolean getValue() {
 		return this.value;

li.strolch.model/src/main/java/li/strolch/model/parameter/DateParameter.java

@@ -55,6 +55,7 @@ public class DateParameter extends AbstractParameter<Date> {
 		return ISO8601FormatFactory.getInstance().formatDate(this.value);
 	}
 
+	@SuppressWarnings("unchecked")
 	@Override
 	public Date getValue() {
 		return this.value;

li.strolch.model/src/main/java/li/strolch/model/parameter/DurationParameter.java

@@ -53,6 +53,7 @@ public class DurationParameter extends AbstractParameter<Long> {
 		return ISO8601FormatFactory.getInstance().formatDuration(this.value);
 	}
 
+	@SuppressWarnings("unchecked")
 	@Override
 	public Long getValue() {
 		return this.value;

li.strolch.model/src/main/java/li/strolch/model/parameter/FloatListParameter.java

@@ -75,6 +75,7 @@ public class FloatListParameter extends AbstractParameter<List<Double>> implemen
 		return sb.toString();
 	}
 
+	@SuppressWarnings("unchecked")
 	@Override
 	public List<Double> getValue() {
 		return new ArrayList<>(this.value);

li.strolch.model/src/main/java/li/strolch/model/parameter/FloatParameter.java

@@ -54,6 +54,7 @@ public class FloatParameter extends AbstractParameter<Double> {
 		return Double.toString(this.value);
 	}
 
+	@SuppressWarnings("unchecked")
 	@Override
 	public Double getValue() {
 		return this.value;

li.strolch.model/src/main/java/li/strolch/model/parameter/IntegerListParameter.java

@@ -75,6 +75,7 @@ public class IntegerListParameter extends AbstractParameter<List<Integer>> imple
 		return sb.toString();
 	}
 
+	@SuppressWarnings("unchecked")
 	@Override
 	public List<Integer> getValue() {
 		return new ArrayList<>(this.value);

li.strolch.model/src/main/java/li/strolch/model/parameter/IntegerParameter.java

@@ -58,6 +58,7 @@ public class IntegerParameter extends AbstractParameter<Integer> {
 		return Integer.toString(this.value);
 	}
 
+	@SuppressWarnings("unchecked")
 	@Override
 	public Integer getValue() {
 		return this.value;

li.strolch.model/src/main/java/li/strolch/model/parameter/LongListParameter.java

@@ -75,6 +75,7 @@ public class LongListParameter extends AbstractParameter<List<Long>> implements
 		return sb.toString();
 	}
 
+	@SuppressWarnings("unchecked")
 	@Override
 	public List<Long> getValue() {
 		return new ArrayList<>(this.value);

li.strolch.model/src/main/java/li/strolch/model/parameter/LongParameter.java

@@ -53,6 +53,7 @@ public class LongParameter extends AbstractParameter<Long> {
 		return this.value.toString();
 	}
 
+	@SuppressWarnings("unchecked")
 	@Override
 	public Long getValue() {
 		return this.value;

li.strolch.model/src/main/java/li/strolch/model/parameter/Parameter.java

@@ -45,7 +45,7 @@ public interface Parameter<T> extends StrolchElement, Comparable<Parameter<?>> {
 	 * 
 	 * @return
 	 */
-	public T getValue();
+	public <U extends T>  U getValue();
 
 	/**
 	 * the value of the parameter

li.strolch.model/src/main/java/li/strolch/model/parameter/StringListParameter.java

@@ -75,6 +75,7 @@ public class StringListParameter extends AbstractParameter<List<String>> impleme
 		return sb.toString();
 	}
 
+	@SuppressWarnings("unchecked")
 	@Override
 	public List<String> getValue() {
 		return new ArrayList<>(this.value);

li.strolch.model/src/main/java/li/strolch/model/parameter/StringParameter.java

@@ -54,6 +54,7 @@ public class StringParameter extends AbstractParameter<String> {
 		return StrolchValueType.STRING.getType();
 	}
 
+	@SuppressWarnings("unchecked")
 	@Override
 	public String getValue() {
 		return this.value;