Saving changes on project run no longer saves all open files (just those...

... that belong to active project). Added PolycodeEditorManager::saveFilesForProject().

Previously, the save and run functionality saved all open editors, and if you had unsaved files opened in other open projects, those would also get saved (which is probably undesirable). (Also, in the actual commit message, I messed up the name of the new method I added, so don't pay attention to that. The one above is correct.)