HackStudio: Move everything into the HackStudio namespace

DevTools/HackStudio/Project.cpp

@@ -36,6 +36,8 @@
 #include <sys/stat.h>
 #include <unistd.h>
 
+namespace HackStudio {
+
 struct Project::ProjectTreeNode : public RefCounted<ProjectTreeNode> {
     enum class Type {
         Invalid,
@@ -358,3 +360,5 @@ void Project::rebuild_tree()
     m_root_node = move(root);
     m_model->update();
 }
+
+}