fix type in rdbSaveKeyValuePair() when saving an intset. Don't merge this commit into 2.2 as will not apply cleanly.

save ziplist encoded type as a different type id. Done as separated commit since this is the part that will not merge cleanly in 2.2

fixed color support for test suite. Now colors are shown as long as there is xterm somewhere inside the TERM env var

fixed two diskstore issues, a quasi-deadlock creating problems with I/O speed and a race condition among threads

propagate key eviction to slaves and AOF, like for expires, so that replicas and AOFs are always consistent even in maxmemory mode.

Fixed a theoretical non exploitable security bug reported by @chrisrohlf. In theory if we undefine SDS_ABORT_ON_OOM from sds.c AND modify zmalloc.c in order to don't quit on out of memory (but this would break every other part of Redis), on out of memory there is a possible heap overflow.

INFO commandstats section reset with config resetstat, a new microseconds per call field, and a few other minor things