Added redisassert.h as drop in replacement for assert.h.
Added redisassert.h as drop in replacement for assert.h.

By using redisassert.h version of assert() you get stack traces in the
log instead of a process disappearing on assertions.

JackieXie168/redis,JackieXie168/redis,JackieXie168/redis,JackieXie168/redis