New transfer tool for Linux: HPex

[Liam Hays]

Thank you. I need to mention, though, that I'm not spending too much time on HPex right now. I'll probably come back, but frankly I realized that the userbase for HPex is (sadly) almost pointlessly small. I think I'll have more time over the summer to finish the changes I've started so far. I have already completed plenty of work on integrating support for the XModem server as well as running on Windows, and I'd rather not leave that abandoned.