FocusGained FocusLost autocmd missing nomodeline

Issue#591: Auto folds close when loosing focus.

The interaction between neovim-qt calling FocusLost and modelines can cause
folds to disappear on their own. This behavior is divergent from nvim.

This fix takes a similar solution/approach to the following:
onivim/oni#575

src/gui/shell.cpp

@@ -1351,16 +1351,17 @@ void Shell::closeEvent(QCloseEvent *ev)
 void Shell::focusInEvent(QFocusEvent *ev)
 {
 	if (m_attached) {
-		// See neovim-qt/issues/329 the FocusGained key no longer exists, use autocmd instead
-		m_nvim->api0()->vim_command("if exists('#FocusGained') | doautocmd FocusGained | endif");
+		// Issue #329: The <FocusGained> key no longer exists, use autocmd instead.
+		m_nvim->api0()->vim_command("if exists('#FocusGained') | doautocmd <nomodeline> FocusGained | endif");
 	}
 	QWidget::focusInEvent(ev);
 }
 
 void Shell::focusOutEvent(QFocusEvent *ev)
 {
 	if (m_attached) {
-		m_nvim->api0()->vim_command("if exists('#FocusLost') | doautocmd FocusLost | endif");
+		// Issue #591: Option <nomodeline> prevents unwanted interaction, consistent with nvim.
+		m_nvim->api0()->vim_command("if exists('#FocusLost') | doautocmd <nomodeline> FocusLost | endif");
 	}
 	QWidget::focusOutEvent(ev);
 }