NWR04B: Checksum closer for new firmware

Ha! In the Runtop firmware, there's the strings "Repotec" and "ip2014". Sure enough, a Google on the latter turns up lots of references to the IP2014 router from Repotec. This version of their firmware has the same structure as the Network Everywhere and Runtop firmware: bootloader + application.bin.gz. However, the firmware is much more similar to the RT bootloader (the one I haven't figured out the checksum for yet). The length is the same, but different md5sum. A quick diff of the hexdump outputs turns up this:

diff ../original_runtop/bl.hd bl.hd
1,4c1,4
< 00000000  06 00 00 ea 02 00 00 00  03 00 00 00 03 13 00 02  |................|
< 00000010  02 00 00 00 5f 6c 0a 00  cd 33 6e 05 67 02 00 00  |...._l...3n.g...|
< 00000020  13 00 00 ea 02 00 00 00  03 00 00 00 03 13 00 02  |................|
< 00000030  02 00 00 00 3f 6c 0a 00  4b 30 6e 05 c2 01 00 00  |....?l..K0n.....|
---
>  00000000  06 00 00 ea 02 00 00 00  0a 00 00 00 02 12 00 1b  |................|
>  00000010  02 00 00 00 6c 6b 09 00  26 27 e7 04 55 02 00 00  |....lk..&'..U...|
>  00000020  13 00 00 ea 02 00 00 00  0a 00 00 00 02 12 00 1b  |................|
>  00000030  02 00 00 00 4c 6b 09 00  05 24 e7 04 11 02 00 00  |....Lk...$......|

...which means this is where the checksum must be!