Use elgg_get_config() instead of the $CONFIG variable.

In Elgg 1.9 $CONFIG variable isn't automatically available for actions anymore so use elgg_get_config() instead.
Merge pull request #45 from juho-jaakkola/actions

Use elgg_get_config() instead of the $CONFIG variable.
Fixes header of plugin project page

The old way of displaying the title didn't play well with the current way of displaying the page header.
Merge pull request #46 from juho-jaakkola/plugin_header

Fixes header of plugin project page.
Corrections of code deprecated since Elgg 1.8
Removal of deprecated $vars['config'] key usages
Manifest update