OP is crazy. To sign your apps, you need to have the original source code and build it using Xcode with your registered developer profile.
If OP wants to " stop it from asking me if I want to allow incoming connections each time I restart my computer or restart the app", he should follow anzio's instructions on how to set an exception in the OS X Firewall policy. You can also simply disable the OS X firewall, which will prevent the message from coming up for all applications.
The message OP is complaining about actually has nothing to do with the signing of an application, and only has to do with the firewall. Application signing only applies to the first run of an application, and all rules regarding signed apps can be turned off by going to System Preferences > Security & Privacy > Allow apps download from and selecting "Anywhere".