Installer Improvements

[commandblockguy]

The current installer is inadequate, and I want to rewrite it. The new installer should support the following:

• Bundling small apps into the installer program itself
• Option to set installer description / icon
• Option to launch the app after installing it, useful for e.g. hooks
• Linear archive space requirements (e.g. don't allocate the entire app at the same time that the appvars containing data are still around, so that apps larger than half the size of the archive can be installed)
• A progress bar, since installation of large apps can take quite a while
• Probably more that I'm forgetting, feel free to comment with feature requests

A few other related thoughts:
It might also be helpful to have a calculator-side program that can turn an app back into an installer, for the purpose of preserving the app across entering and leaving test mode, or for sending an app between two calculators without needing a computer. This could potentially be a standalone program, built-in to generated apps (as a hook that activates on the memory management screens), or a feature of a shell.
You could also have an "online" installer, either by modifying prgmTRANSFER to accept apps, or by writing a custom program that implements TI's protocol (which would also enable unit-to-unit transfers).

I'm not too familiar with what exactly gets deleted in test modes - do groups stick around?