AK: Let's call decrementing reference counts "unref" instead of "deref"

It always bothered me that we're using the overloaded "dereference"
term for this. Let's call it "unreference" instead. :^)

Libraries/LibGUI/GVariant.cpp

@@ -61,13 +61,13 @@ void GVariant::clear()
 {
     switch (m_type) {
     case Type::String:
-        AK::deref_if_not_null(m_value.as_string);
+        AK::unref_if_not_null(m_value.as_string);
         break;
     case Type::Bitmap:
-        AK::deref_if_not_null(m_value.as_bitmap);
+        AK::unref_if_not_null(m_value.as_bitmap);
         break;
     case Type::Icon:
-        AK::deref_if_not_null(m_value.as_icon);
+        AK::unref_if_not_null(m_value.as_icon);
         break;
     default:
         break;

Libraries/LibHTML/TreeNode.h

@@ -48,7 +48,7 @@ public:
         ++m_ref_count;
     }
 
-    void deref()
+    void unref()
     {
         ASSERT(m_ref_count);
         if (!--m_ref_count) {
@@ -60,7 +60,7 @@ public:
             for (auto* child = m_first_child; child; child = next_child) {
                 next_child = child->m_next_sibling;
                 child->m_parent = nullptr;
-                child->deref();
+                child->unref();
             }
             delete static_cast<T*>(this);
         }
@@ -221,7 +221,7 @@ inline NonnullRefPtr<T> TreeNode<T>::remove_child(NonnullRefPtr<T> node, bool ca
     if (call_removed_from)
         node->removed_from(static_cast<T&>(*this));
 
-    node->deref();
+    node->unref();
 
     return node;
 }

Libraries/LibThread/BackgroundAction.h

@@ -81,11 +81,11 @@ private:
             if (m_on_complete) {
                 CEventLoop::main().post_event(*this, make<CDeferredInvocationEvent>([this](CObject&) {
                     m_on_complete(m_result.release_value());
-                    this->deref();
+                    this->unref();
                 }));
                 CEventLoop::main().wake();
             } else
-                this->deref();
+                this->unref();
         });
     }