Delete unnecessary files (Debug\Obj\*, *.dep, settings\*, *.sfr, *.tmp)
Update IAR projects to support IAR 5.52.
Remove use of UPCS0 in usb.c since it's no longer supported (devices will select XTAL by default, XT2 for all current devices).
Enable TCK pin (PJ.3) for hardware entry sequence of devices without TEST pin.