This commit allows Redis to set a process name that includes the binding
address and the port number in order to make operations simpler.

Redis children processes doing AOF rewrites or RDB saving change the
name into redis-aof-rewrite and redis-rdb-bgsave respectively.

This in general makes harder to kill the wrong process because of an
error and makes simpler to identify saving children.

This feature was suggested by Arnaud GRANAL in the Redis Google Group,
Arnaud also pointed me to the setproctitle.c implementation includeed in
this commit.

This feature should work on all the Linux, OSX, and all the three major
BSD systems.

The idea is to be able to identify a build in a unique way, so for
instance after a bug report we can recognize that the build is the one
of a popular Linux distribution and perform the debugging in the same
environment.

This commit implements the first, beta quality implementation of Redis
Sentinel, a distributed monitoring system for Redis with notification
and automatic failover capabilities.

More info at http://redis.io/topics/sentinel

bitop.c contains the "Bit related string operations" so it seems more
logical to call it bitops instead of bitop.
This also makes it matching the name of the test (unit/bitops.tcl).

All the general string operations are implemented in t_string.c, however
the bit operations, while targeting the string type, are better served
in a specific file where we have the implementations of the following
four commands and helper functions:

    GETBIT
    SETBIT
    BITOP
    BITCOUNT

In the future this file will probably contain more code related to
making the BITOP and BITCOUNT operations faster.

A previous commit removed -g -rdynamic -ggdb as LDFLAGS, not allowing
Redis to produce a stack trace wth symbol names on crash.
This commit fixes the issue.

This is not needed because every change in compiler/linker flags
triggers a cleanup.

This reflects that REDIS_*FLAGS will only be used for compilation of
Redis and not for its dependencies. Similarly, that FINAL_*FLAGS are
composed of other variables and holds the options that are finally
passed to the compiler and linker.

I modified it for error in a previous commit doing search & replace.

Makefile now introduces Redis-specific CFLAGS / LDFLAGS. Gcov target fixed. Added comments to describe how it works.

Remove unused variables. Instead of overriding non-standard variables
such as ARCH and PROF, use standard variables CFLAGS and LDFLAGS to
override Makefile settings. Move dependencies generated by `make dep` to
a separate file.

needed when installing a new Redis version. Thanks to Scott Kevill.
Fixes issue #335.

To do so, the Makefile stores the contents of the MALLOC environment
variable in a file named .make-malloc. When the contents of this file
and the MALLOC variable are not equal, it forces a rebuild of the Redis
source tree.

A side-effect of this change is that choosing an allocator can now be
done using the single MALLOC variable instead of USE_TCMALLOC,
USE_JEMALLOC and so forth. These variables continue to work for
backwards compatibility.

This change moves the build instructions for dependencies to a separate
Makefile in deps/. The ARCH environment variable is stored in a
.make-arch file in the same directory as the Makefile. The contents of
this file is read and compared to the current ARCH, and, on a mismatch
triggers rebuilding the entire source tree.

When file .make-arch exists and matches with ARCH from the environment,
the dependencies are assumed to already be built.

The new "clean" target only cleans the Redis source tree, not its
dependencies. To clear the dependencies as well, the "distclean" target
can be used.

Revert "Use the new install script as make install target. Message about install script requiring root changed a bit to make it more evident."
After talking with Pieter he changed my mind about this, it is better to
have a simpler install script that works everywhere, and the complex one
can be always executed if needed by hand. We'll make possibly a new
target for the full featured installation script, and even suggest it
after a Make install.

This reverts commit f1e60d75.