Libraries: Create top level directory for libraries.

Things were getting a little crowded in the project root, so this patch
moves the Lib*/ directories into Libraries/.

Libraries/LibHTML/CSS/Selector.cpp

@@ -0,0 +1,35 @@
+#include <LibHTML/CSS/Selector.h>
+
+Selector::Selector(Vector<Component>&& components)
+    : m_components(move(components))
+{
+}
+
+Selector::~Selector()
+{
+}
+
+Specificity Selector::specificity() const
+{
+    unsigned ids = 0;
+    unsigned tag_names = 0;
+    unsigned classes = 0;
+
+    for (auto& component : m_components) {
+        switch (component.type) {
+        case Component::Type::Id:
+            ++ids;
+            break;
+        case Component::Type::Class:
+            ++classes;
+            break;
+        case Component::Type::TagName:
+            ++tag_names;
+            break;
+        default:
+            break;
+        }
+    }
+
+    return { ids, classes, tag_names };
+}