Adding auth_update to old downloadpackage code, not using JHttp
Merge remote-tracking branch 'joomla-cms/2.5.x' into auth_update_2.5.x

Conflicts:
	libraries/joomla/installer/helper.php
Updated to latest 2.5.x Joomla! dev branch
Merge pull request #2793 from shumisha/auth_update_2.5.x

 Improved Joomla! extensions update handling of paid for extensions to Joomla 2.5.x