PHLEGM v8 firmware cache for PET-2001-32N-BASIC4

No ROM binaries are shipped by PHLEGM.
Slots, addresses, byte lengths, CRC32 checksums and download URLs are in firmware.config.phlegm.
With Networking enabled, missing firmware is fetched and verified before machine startup.
Hardware profile: PET 2001-32N with later BASIC 4.0 upgrade, normal/graphics keyboard, 40x25 TTL (pre-CRTC editor ROM 901447-29).
RAM address range: $0000-$7FFF; memory size: 32 KiB.
Firmware slots: 6
