Missing assert removal from sdsIncrLen()

Companion for 8eeb1802ec42682a614a5ebca318a0ba44ca7c03, but dealing with hiredis.
Merge pull request #1964 from mariano-perez-rodriguez/patch-2

Missing assert removal from sdsIncrLen()
Missing va_end also added in hiredis copy of sds.c.
Use long for rehash and iterator index in dict.h.

This allows to support datasets with more than 2 billion of keys
(possible in very large memory instances, this bug was actually
reported).

Closes issue #1814.
Cast to right type in dictNext().

This closes issue #1929, the other part was fixed in the context of issue
Fix dictRehash assert casting type.

Also related to #1929.
Improve disable save comment in redis.conf

Closes #1897
Remove surplus double quotes

Closes #1877
Update linenoise accessory files

The core linenoise code was being backported, but not
the README or example.  It's less confusing for users
if everything matches across directories.

Fix inspired by @thrig

Closes #1872
Fix many small typos

Closes #1871
Fix incorrect comments

error != success; and 0 != number of bytes written

Closes #1806
Fix typo in redis.conf

Closes #1713
Fix typo

Closes #1682
Fix typo in 00-RELEASENOTES

Closes #1673
Fix typo

Closes #1544
Fix typo: ad -> and

Closes #1537
Fix typos

Closes #1513
Grammar and typo fixes in redis.conf

Closes #1441
Fix typo in redis.h

Closes #1386
Fix on-place -> in-place

Closes #1373