Release 2.5.2 - Platform.IO, FreeRTOS, SD/SDFS fixes

• Remove binary info header, was crashing picotool (#831)
• Use pipes between GCC stages (#827)
• Add upsteam multicast compatibility APIs (#821)
• Clean up WebServer send() methods (#820)
• Add SDFS header to SpeedTest to simplify use
• Add bidirectional bulk SPI transfer, update SdFAT (#819)
• Shrink MIME table flash usage by ~500 bytes (#818)
• Avoid potential lockup w/Serial.read unconnected (#817)
• Fix WiFi MAC Address string output (#812)
• Don't re-initialize ADC for every reading (#808)
• Protect core/Newlib mutexes from task preemption under FreeRTOS (#798)
• Add ExtremeElectric JSON
• Identify boards when in compound USB device mode (#806)
• Add Home Assistant starter to tutorials listing (#804)