implemented --single, --list-tests. --accurante and --help are now recognized but not actually implemented.

no longer prints testing... but just shows the test when we get the final result from the testing client.

replication test split into three parts in order to improve test execution time. Random fixes and improvements.

Initial implementation of a client-server parallel testing system for Redis in order to speedup execution of the test suite.

fixed bgsave_in_progress in INFO when BGSAVEing with diskstore enabled, don't DEBUG FLUSHCACHE when bgsave is in progress.

redis-cli tests commented out since there is a problem with the CI server and this tests, will be activated again once the problem is fixed

Changed redis-cli to output the raw response for a bulk reply when it is
run in interactive mode instead of checking isatty.