Fix a bug when the first parameter is not a group of captcha.
fixed Unicode support in Captcha_Word
fixed Unicode support in Captcha class
Fix using Kohana Config Reader in Kohana 3.2

@see http://kohanaframework.org/3.2/guide/kohana/config#groups
Merge pull request #13 from bistory/master

Fix a bug with the group parameter
Merge pull request #17 from davidvandertuijn/master

Fix using Kohana Config Reader in Kohana 3.2
Merge pull request #1 from kolanos/master

sources update