experimental arm NEON cpu algo modeled after sse2 4way algo

Notes: several hacks were needed to get her running.

must pass CFLAGS="-g -O2 -mfpu=neon" ./configure for it to compile. or directly modify bfgminer_CPPFLAGS in  generated Makefile

reported hash rate on BBB ~305kHash/sec


did not run long enough to find nonce (validation that code is correct) but it was directly modeled after sha256_4Way.c only modifying the sse2 intrinsics to NEON 
![screen shot 2013-12-26 at 1 11 41 am](https://f.cloud.github.com/assets/1194617/1809645/1b4e85a8-6dfc-11e3-8f4c-874942777919.png)