Custom curl implementation with questionable options

[mudrd8mz]

Moodle has a wrapper class curl for the cURL extension which should be used instead of low-level curl functions. The wrapper respects all the other Moodle settings such as proxy and others.

Additionally, turning off options like CURLOPT_SSL_VERIFYPEER is not a good practise and should be avoided.

[vibhavsinha]

I have removed the insecure option CURLOPT_SSL_VERIFYPEER with this commit 6d6f6ac.

Replacing low-level curl with the moodle wrapper class is still pending, hence keeping this issue open.