Assess modchip compatibility status

[9ary]

• PicoBoot should be actively supported. See IPL binary processing webhdx/PicoBoot#22 for our relationship with them.
• Qoob Pro and ViperGC Extreme should still be supported, as they have plenty of flash. Testing is needed.
• ViperGC should still fit as well. Testing is needed in case it requires compression, but otherwise it works completely identically to VGCE.
• Qoob SX is the trickiest because it's hard to make things fit on it. Support may be put on hold.
• Xeno (xenopie) support should be yote. I don't think anyone was ever able to test it properly and it's now completely obsolete. It was also specific to my Raspberry Pi-based Xeno clone which was absolutely awful, because no AVR has enough memory to hold iplboot. (fixed in Makefile updates #9)
• boot.gci support (for game exploits) should be maintained as well. (compressed GCI file not working with save exploit #27)