Changelog for 1.4.3

[gtirloni]

Version 1.4.3 was released on Rubygems but I can't find a tag here and/or a changelog to know what exactly changed in that version.

[pelargir]

Same situation here. The existing changelog is quite outdated.

[gtirloni]

https://my.diffend.io/gems/yajl-ruby/1.4.2/1.4.3

[gtirloni]

CC @jhawthorn @brianmario