PrefService: deprecate clear(Class, String)

This is the same thing as remove(Class, String).

Actually, in the Preferences API, clear and removeNode are not the same:
removeNode is recursive, whereas clear just clears keys at the current
node and not below. But the latter non-recursive behavior is not
something we want to expose via the PrefService API.

Author: ctrueden

src/main/java/org/scijava/prefs/DefaultPrefService.java

@@ -165,11 +165,6 @@ public void clearAll() {
 			prefs(name).removeNode();
 	}
 
-	@Override
-	public void clear(final Class<?> c, final String name) {
-		prefs(c).clear(name);
-	}
-
 	@Override
 	public void remove(final Class<?> c, final String name) {
 		prefs(c).remove(name);
@@ -297,6 +292,12 @@ public void putIterable(final Iterable<String> iterable, final String key) {
 		putIterable((Class<?>) null, iterable, key);
 	}
 
+	@Deprecated
+	@Override
+	public void clear(final Class<?> c, final String name) {
+		prefs(c).clear(name);
+	}
+
 	// -- Helper methods --
 
 	private SmartPrefs prefs(final Class<?> c) {

src/main/java/org/scijava/prefs/PrefService.java

@@ -86,11 +86,6 @@ default String get(final Class<?> c, final String name) {
 	/** Clears everything. */
 	void clearAll();
 
-	/**
-	 * Clears the node indexed under the given class.
-	 */
-	void clear(Class<?> c, String name);
-
 	/** Removes the node. */
 	void remove(Class<?> c, String name);
 
@@ -264,4 +259,7 @@ default void clear(final String key) {
 
 	@Deprecated
 	Iterable<String> getIterable(String key);
+
+	@Deprecated
+	void clear(Class<?> c, String name);
 }