Add self-upgrade command - #55

All committers have signed the CLA.

I'm working on a lot of enhancements to make this setup more attractive to developers in addition to researchers. There are some rough spots, but I'm wondering if its something you'd be willing to incorporate or not.

The README changes outline the differences and augmentations I'm currently working through.

If someone from Trail of Bits wants to have a conversation about those changes, feel free to reach to [email protected].

Thanks for sharing this tool with everyone!

Hi! Thanks for your contribution, that's really appreciated.

Just a question, why would we want a new 'self-upgrade' command, and not use the update command? Can you explain a bit more your use-case here?

If developers are checking out a version of the tool, and the self-install command obviates the need for them to remember where the tool is checked out, having a self-upgrade command make it easier to keep things in step.

As an example, I was having someone test my branch and it was easier to say run devc self-upgrade then to run cd "$(dirname "$(realpath "$(which devc)")")" && git pull && cd -

This is just a convenience feature.