Option: create project automatically when a folder is opened

Add an option which makes Sublime Text 2 create a project automatically when a folder is opened for the first time*.

The name of the project files should be equal to the folder name and stored in the folder root.

The project should be loaded automatically the next time the folder is opened.

Interesting additional options might be:

- By default, give no name to the project files on Mac & Linux (.project and .workspace)

- Create a folder to keep all the project files together 

*(A folder can be opened either by dragging it to the icon or by using the new menu item: Open Folder)