Make letter cases consistent in menus and widgets

In various menu options letter cases were not consistent. This was also
the case within various debugging widgets. This attempts to make letter
cases consistent, but it is of course a matter of opinion which way is the
correct one.

src/citra_qt/debugger/callstack.cpp

@@ -14,9 +14,9 @@ CallstackWidget::CallstackWidget(QWidget* parent): QDockWidget(parent)
 
     callstack_model = new QStandardItemModel(this);
     callstack_model->setColumnCount(4);
-    callstack_model->setHeaderData(0, Qt::Horizontal, "Stack pointer");
-    callstack_model->setHeaderData(2, Qt::Horizontal, "Return address");
-    callstack_model->setHeaderData(1, Qt::Horizontal, "Call address");
+    callstack_model->setHeaderData(0, Qt::Horizontal, "Stack Pointer");
+    callstack_model->setHeaderData(2, Qt::Horizontal, "Return Address");
+    callstack_model->setHeaderData(1, Qt::Horizontal, "Call Address");
     callstack_model->setHeaderData(3, Qt::Horizontal, "Function");
     ui.treeView->setModel(callstack_model);
 }