Update version of the original Joomla15captcha (based on JC45_Inst_JCaptha451.zip) to make it working on J1.5 & J1.6 & J1.7, added upgrade mode (don't need to delete) and add French language files

Tested with kunena 1.6.5 on J1.7 too. To use it with Kunena 1.6.x , just install, activated (of course) the pluggin 'Sytem - Captcha' and in the plugin parameters add kunena.post in the field 'Enabled captchas' ...that's all for the plugin. In kunena, enable the patcha usage.

The pack is available for download on donwload page.