Update AbstractCurl.php

Updating `prepare()` so that it considers the current PHP environment. `safe_mode` and `open_basedir` will not allow `cURL` to `FOLLOWLOCATION`.

See also: http://www.edmondscommerce.co.uk/curl/php-curl-curlopt_followlocation-and-open_basedir-or-safe-mode/
Update AbstractCurl.php

Using camelCase and removing brackets.
Merge pull request #125 from JasWSInc/master

cURL Compatibility Improvement
Override php.ini setting *arg_separator.output*
Merge pull request #126 from KoernerWS/patch-1

Override php.ini setting *arg_separator.output*
[curl] allow set custom file name on upload.
Merge pull request #132 from formapro-forks/curl-custom-filename

[curl] allow set custom file name on upload.