Changes required for json and multiserver testing support

[sakows]

No description provided.

[sakows]

To compile in MAC OSX:

make MACOSX_DEPLOYMENT_TARGET=10.14 

To Run test:

./wrk -t2 -d2s -c10 -R10 -s scripts/multiple-endpoints_in_json.lua https://gmail.com:443 https://google.com:443 https://youtube.com:443

Output:

{
"TotalRequests": "22",
"DurationInMicroseconds": "2017624.00",
"Bytes": "10668",
"RequestsPerSec": "10.90",
"BytesTransferPerSec": "5287.41",
"MinLatency": "41312.00",
"AvgLatency": "289225.60",
"MaxLatency": "714752.00",
"StdDev": "210681.51",
"Url_0": "https://gmail.com:443",
"UrlRequestCount_0": 4
"Url_1": "https://google.com:443",
"UrlRequestCount_1": 10
"Url_2": "https://youtube.com:443",
"UrlRequestCount_2": 8
"Percentiles": [
                {
"Count": "10",
"Percent": "50",
"Value": "184.959000"
                },
                {
"Count": "15",
"Percent": "75",
"Value": "317.183000"
                },
                {
"Count": "18",
"Percent": "90",
"Value": "616.447000"
                },
                {
"Count": "20",
"Percent": "99",
"Value": "715.263000"
                },
                {
"Count": "20",
"Percent": "99.9",
"Value": "715.263000"
                },
                {
"Count": "20",
"Percent": "99.99",
"Value": "715.263000"
                },
                {
"Count": "20",
"Percent": "99.999",
"Value": "715.263000"
                },
                {
"Count": "20",
"Percent": "100",
"Value": "715.263000"
                }
        ]
}

[orefalo]

can you maybe explain what this PR is all about?
taken out of context the one line description is cryptic...