If we woke up to accept a connection, but we can't
accept it, inform the user of the error going on
with their networking.

(The previous message was the same for success or error!)

Otherwise there are security risks, especially when providing Redis as a
service, the user may "sniff" for admin commands renamed to an
unguessable string via rename-command in redis.conf.

The old list did not made much sense... and the flag is currently not
used at all, so no side effects.

It fixes a bad bug that crashes the server in certain conditions
as shown in issue #2210.

Related to #2094.

People mostly use SORT against lists, but our prior
behavior was pretending lists were an unordered bag
requiring a forced-sort when no sort was requested.

We can just use the native list ordering to ensure
consistency across replicaion and scripting calls.

Closes #2079
Closes #545 (again)

status command currently reports success when redis has crashed and the pid file still exists. Changing to check the actual process is running.

Fix function prototype in redis-cli.c.

    if redis works in cluster-mode and redis-cli was run with argv, reconnect if needs.
    example:
    ./redis-cli set foo bar

    if return is MOVED redis-cli just do nothing.

Fix two typos in redis.conf:

- "trnasfers" --> "transfers"
- "enalbed" --> "enabled"

10000 completes in a too short time and may easily provide unreliable
figures because of tiny duration.

bulk_data field size was not removed from the count. It is not possible
to declare it simply as 'char bulk_data[]' since the structure is nested
into another structure.

Improved getting pid

See https://sourceware.org/glibc/wiki/Release/2.20#Packaging_Changes

```sh
$ ~ pidof redis-server
# nothing

$ ~ ps aux | grep [r]edis
redis      593  0.0  0.0  36900  5564 ?        Ssl  Dec02   1:37 /usr/bin/redis-server 127.0.0.1:6379
klay     15927  0.0  0.0  16772  6068 pts/6    S+   13:58   0:00 redis-cli

$ ~ uname -a
Linux edge 3.17.4-1-ARCH #1 SMP PREEMPT Fri Nov 21 21:14:42 CET 2014 x86_64 GNU/Linux
```

This allows shell pipes to correctly end redis-cli.

Ref #2066

Thanks to @badboy for the help in checking the build after the fix.

Track bandwidth used by clients and replication (but diskless
replication is not tracked since the actual transfer happens in the
child process).

This includes a refactoring that makes tracking new instantaneous
metrics simpler.

Closes issue #1935.