captcha 6.x-2.5

Changes since 6.x-2.4:

• #1701050: replace strtolower() with drupal_strtolower()
• #1597970 by drupalishsandip and soxofaan: PHP sucks at comparing strings that look like numbers
• be more explicit in $form_state['captcha_info'] about this and posted form_id
• #1479370 by Robin Millette: added isset check for undefined property stdClass::$captcha_type
• #960270: no need anymore for workaround for CAPTCHA on login forms
• GD library availability check should look for imagepng function (which is required), not imagejpeg (which is optional). Related to issue #1337366.
• #1024370: Make sure we can use a top level form value $form_state['values']['captcha_response'], even if the form has #tree=true.
• properly sort result of ctools_export_load_object for on settings page. (follow up of of issue #825088)
• Preloaded captcha points default to 'none' (follow up of issue #825088)
• #825088: tweaked patch from comments #9 and #12
• refactored captcha_get_captcha_points helper function to (part of issue #825088)
• first simple implementation: click image for reload
• remove unneeded id-attribute on captcha description
• #1142606: added css class to CAPTCHA admin links fieldset
• #976436 by matheusgorino, soxofaan: Adds an ob_end_clean to prevent the output image from being corrupted.
• removing aditional empty line in the end of file
• minor change in the readme file
• Removing translation directories
• Stripping CVS keywords
• one of my better commits
• #893810: CAPTCHA should also be possible on login block on "access denied" admin pages