Check curl_exec as well as curl_version

I think I've seen cases where web hosts have got Curl installed, but disable it via disabling the function curl_exec (the function that actually causes network activity). In this case, the check for curl_version alone will give a misleading result. Hence this tweak.
Merge pull request #159 from ianbarber/master

Delete big test file
Merge pull request #157 from DavidAnderson684/patch-2

Check curl_exec as well as curl_version
Updated AppState.php
Updated SQLAdmin.php
Set CURLOPT_URL before CURLOPT_CUSTOMREQUEST

One of my users reports this PHP warning:
"Warning: Can't set CURLOPT_CUSTOMREQUEST before CURLOPT_URL in Google/IO/Curl.php
on line 57"

Hence, this tweak.
Updated Mirror.php
Updated Doubleclicksearch.php
Replaced non existing variable $now with mktime().
Fixes #167
Updated MapsEngine.php
Updated AdExchangeBuyer.php
Updated Games.php
Merge pull request #168 from chixor/master

Replaced non existing variable $now with mktime().
Updated MapsEngine.php
Updated Analytics.php
Updated IdentityToolkit.php
Merge pull request #162 from DavidAnderson684/patch-3

Set CURLOPT_URL before CURLOPT_CUSTOMREQUEST
Updated Books.php
Updated Calendar.php
Added service Replicapool.php