If no valid keys are found when processing an HMGET command,
free up our command and keys pointer and simply return FALSE.

Addresses #379
Add a unit test for the scenario described in #379
Merge branch 'hotfix/hmget_invalid_args' into develop

Conflicts:
	redis.c
	tests/TestRedis.php
Fix a merge fail
Merge branch 'hotfix/close_command' into develop
Merge branch 'hotfix/setex_long_expires' into develop
Merge branch 'hotfix/srandmember_serialize' into develop
Merge branch 'hotfix/redis_array_pconnect' into develop
Merge branch 'hotfix/bitops_offset' into develop
Merge branch 'hotfix/allow_null_set_options' into develop
Merge branch 'hotfix/incrby_float_prefix' into develop

Fixes #408
Implement WAIT command

This commit implements the new WAIT command which currently lives
in redis unstable, along with a unit test.

Also added myself to the README.markdown file, as well as a link to
"the twitter".
SCAN and variants

This commit introduces support for the Redis SCAN, HSCAN, SSCAN,
and ZSCAN commands.

In the case of HSCAN, SSCAN, and ZSCAN, we take a key and iterator
as required arguments, and for SCAN just an iterator.  Matching
the Redis commands, each variant can optionally take a pattern
to match against and a count value which hints at Redis how many
keys to return at a time.

When scanning keys or members (especially with a large keyspace when
searching for a pattern), Redis will sometimes return an empty result
of keys/members.  PHPRedis can be set up to abstract this from the
caller by setting:

$redis->setOption(Redis::OPT_SCAN, Redis::SCAN_RETRY);

Which instructs PHPRedis to keep retrying the scan until members are
returned OR the iteration completes (Redis returns to us a zero iterator).

By default this option is set to Redis::SCAN_NORETRY, meaning that
empty results are possible, requiring an explicit check for FALSE in the
scanning loop, like so:

```php
$it = NULL;
while(($arr_keys = $redis->scan($it, "*pattern*"))!==FALSE) {
	print_r($arr_keys);
}
```
Documentation fix
Another documentation fix :)
Merge branch 'feature/scan_commands' into develop
Don't forget to prefix our keys.  :)
Minor documentation fixes
added homebrew installation instructions
Update README.markdown

fixed syntax error in set examples.