Added a note about rapidjson to the API changes in the CHANGELOG.
Added a note about rapidjson to the API changes in the CHANGELOG.

JSON endpoints now use rapidjson to provide a performance improvement,
this means that if a client has a JSON de-serializer that does not
conform to the ECMA-404 spec for JSON, they may break. As an example,
Mesos would previously serialize '/' as '\/', but the spec does not
require the escaping and rapidjson does not escape '/'.

abudnik/mesos,jpeach/mesos,reneploetz/mesos,abudnik/mesos,chhsia0/mesos,Gilbert88/mesos,kaysoky/mesos,andschwa/mesos,dforsyth/mesos,andschwa/mesos,gsantovena/mesos,chhsia0/mesos,jpeach/mesos,abudnik/mesos,jpeach/mesos,reneploetz/mesos,kaysoky/mesos,gsantovena/mesos,dforsyth/mesos,kaysoky/mesos,andschwa/mesos,Gilbert88/mesos,abudnik/mesos,gsantovena/mesos,Gilbert88/mesos,abudnik/mesos,kaysoky/mesos,kaysoky/mesos,andschwa/mesos,chhsia0/mesos,andschwa/mesos,dforsyth/mesos,jpeach/mesos,gsantovena/mesos,reneploetz/mesos,Gilbert88/mesos,andschwa/mesos,dforsyth/mesos,gsantovena/mesos,gsantovena/mesos,Gilbert88/mesos,chhsia0/mesos,dforsyth/mesos,chhsia0/mesos,jpeach/mesos,andschwa/mesos,jpeach/mesos,reneploetz/mesos,dforsyth/mesos,reneploetz/mesos,kaysoky/mesos,reneploetz/mesos,Gilbert88/mesos,abudnik/mesos,jpeach/mesos,kaysoky/mesos,abudnik/mesos,dforsyth/mesos,Gilbert88/mesos,reneploetz/mesos,chhsia0/mesos,chhsia0/mesos,gsantovena/mesos