USBaspLoader v0.96.4 special release

  - fix an error-checking issue in spminterface.h

Precompiled bootloader v0.96.4 for atmega8 (Rev.3),
default (Rev.3) schematics clocked with 16 MHz
(not all AVRs are tested, yet! But please report!)

sha1sums are (no change since v0.96.1 for default settings):

	d3fd9ccfaff95f5c0001bbb38139ee313341f041        "raw bytecode usbasp"
	b09a10d91e46a80ed1052f24a78615780b51130c        "raw bytecode update"

	c35e94466980d291e85c9be7156bde55e2594c6d        "elf firmware usbasp"
	40a23c1869e2be3c64cdbbb02912eff837336416        "elf firmware update"

	897d1086adc0f1dfd64525034104fc75d74dee68        firmware_usbasploader.hex
	59ec7ab84431119d5ac3c137c71f6e52e34bcec8        update_usbasploader.hex

Signed-off-by: Stephan Baerwolf <stephan.baerwolf@tu-ilmenau.de>