1 The prompt message is:
In order to watch this project, the server must be started. Do you want to start the server?
Actually, if a user start a server in command line, and click start watching in IDE, it should be watch successfully. So we can't use must here.
2. if watching failed, we shouldn't not add [watching] label to the liferay workspace(not sure if this should be fix or not)
(3. According to dev, we can leave the following now If no modules in liferay workspace and start is stopped right click on liferay workspace > Start watching project notice error in console about "Task 'watch' not found in root project 'liferay-workspace'". Because there is no module project in liferay workspace.)