inclusion of curl_code, structural changes to testCurl

testCurl underwent a few major changes:
-> implementation of file writing strategy from the command-line
interface.
-> the functions no longer return arrays, and we don't call the
array_merge function on URLs to improve the computatational time of the
function.
-> return values are primitive types, we don't send back arrays (memory
management better?)

curl_code:
-> Alfred's code, it gives an idea of how to use Curl in php.
-> It also takes care of HTTP error codes