Don't execute sgen on creation

[BeckmaR]

When the user creates a sgen-generator-file (via wizard), it is executed on the spot and code is generated. This can be annoying, especially when the paths are not what the user wanted to have - files are thrown all over the project.

This happens because the sgen file is created, written and saved. On save, the builder is activated. Instead, it might be a good idea to create the file, save it empty, and then write the pre-generated content to it without saving again (leaving it in dirty state), and opening it for the user. This way, the user can inspect it, change the paths (or the language, because we all forget to change Java to C), save it and then get code generated.

Another approach would be to include an option like generate = false, but that seems stupid and is easily overlooked, leading to confusion.

[andreasmuelder]

Add Wizard page to provide additional information for outlet