While ANET_ERR is -1, check syscall retval for -1 itself.
Accept multiple clients per iteration.

When the listening sockets readable event is fired, we have the chance
to accept multiple clients instead of accepting a single one. This makes
Redis more responsive when there is a mass-connect event (for example
after the server startup), and in workloads where a connect-disconnect
pattern is used often, so that multiple clients are waiting to be
accepted continuously.

As a side effect, this commit makes the LOADING, BUSY, and similar
errors much faster to deliver to the client, making Redis more
responsive when there is to return errors to inform the clients that the
server is blocked in an not interruptible operation.
Process events with processEventsWhileBlocked() when blocked.

When we are blocked and a few events a processed from time to time, it
is smarter to call the event handler a few times in order to handle the
accept, read, write, close cycle of a client in a single pass, otherwise
there is too much latency added for clients to receive a reply while the
server is busy in some way (for example during the DB loading).
Test: fixed scripting.tcl test false positive.
Sentinel example config: explain you don't need to specify slaves.
Disable recursive watchdog signal handler

If we are in the signal handler, we don't want to handle
the signal again.  In extreme cases, this can cause a stack overflow
and segfault Redis.

Fixes #1771
More trailing spaces in sentinel.c removed.
Scripting: better Lua number -> string conversion in luaRedisGenericCommand().

The lua_to*string() family of functions use a non optimal format
specifier when converting integers to strings. This has both the problem
of the number being converted in exponential notation, which we don't
use as a Redis return value when floating point numbers are involed,
and, moreover, there is a loss of precision since the default format
specifier is not able to represent numbers that must be represented
exactly in the IEEE 754 number mantissa.

The new code handles it as a special case using a saner conversion.

This fixes issue #1118.
Regression test for issue #1118.
Fixed dbuf variable scope in luaRedisGenericCommand().

I'm not sure if while the visibility is the inner block, the fact we
point to 'dbuf' is a problem or not, probably the stack var isx
guaranteed to live until the function returns. However obvious code is
better anyway.
Tests for min-slaves-* feature.
Don't process min-slaves-to-write for slaves.

Replication is totally broken when a slave has this option, since it
stops accepting updates from masters.

This fixes issue #1434.
Redis 2.8.10.
fix issue 1787
Fix eval usage in tests to conform with eval semantics
Small typo fixed
Fixed typo in word avarege in result message of --intrinsic-latency analyzer
Fix blocking operations from missing new lists

Behrad Zari discovered [1] and Josiah reported [2]: if you block
and wait for a list to exist, but the list creates from
a non-push command, the blocked client never gets notified.

This commit adds notification of blocked clients into
the DB layer and away from individual commands.

Lists can be created by [LR]PUSH, SORT..STORE, RENAME, MOVE,
and RESTORE.  Previously, blocked client notifications were
only triggered by [LR]PUSH.  Your client would never get
notified if a list were created by SORT..STORE or RENAME or
a RESTORE, etc.

Blocked client notification now happens in one unified place:
  - dbAdd() triggers notification when adding a list to the DB

Two new tests are added that fail prior to this commit.

All test pass.

Fixes #1668

[1]: https://groups.google.com/forum/#!topic/redis-db/k4oWfMkN1NU
[2]: #1668
Fix lack of SA_ONSTACK under Cygwin

Fixes #232
Fix lack of strtold under Cygwin

Renaming strtold to strtod then casting
the result is the standard way of dealing with
no strtold in Cygwin.