cjson calls isinf, but some Solaris versions don't have isinf even with the attempted fix we have in deps/Makefile. We can harmlessly include the Redis solarisfixes.h header to give cjson proper isinf. Note: cjson has a compile-time setting for using their own defined isinf, but the Redis definition in solarisfixes.h is more complete. Fixes antirez#1620