Adding request method for easy logging

Add CURLOPT_CUSTOMREQUEST even on methods that will be overrided like
GET, POST and PUT.

This allows logger or debugger to easily retrieve the request method.
Enhanced escape function on Database.php

Escaping only the field name part when specifying a string with
functions or keywords. e.g. DISTINCT, COUNT(ID).

Does nothing when no table is specified when escaping, and the field
contains spaces or parantheses.