Adding Folder Contents to a Project
This option allows you to add, in a single action, several source files to your project, right click on a project and select Add Folder to Project..., a dialog will popup requesting you the folder to add
Once you accept the folder, another dialog will be shown, listing the files found (recursively), in that folder, that matches the masks specified at the top, you can use several masks, separated by ;
You can select the files you want to add to the project by checking the items on the list and clicking "Add selected files to the project" button, will add them to the current project.
The dialog is not closed then, so you can change the mask, click Search again, and keep adding files, once you are done, click on the Cancel button
In the status bar at the bottom, you can check how many files have been found that match the filter and how many you have selected, also, at the bottom, there is a checkbox you can use to check/uncheck all elements in the list.