Debug plugin can display logs.
Made the mode option hidden. Can be changed to 'list' once the platform is updated.
Set the default category to 'deprecated' because that seems sensible.
alphabetized language file
Improved description for 'categories' field.
Fixed typo in translation file
Swapped label and description for logs file
Changed default value of the log_categories field
Code style fixes
Log category names can only contain A-Za-z0-9_.- so make the delimiter for the
category list anything other than those. Officially, it is a comma
separated list.
Pursuant to project's proper procedures (pending petition passage), prefix protected property
Merge branch 'plg_system_debug-logs' of https://github.com/okonomiyaki3000/joomla-cms into plg_system_debug-logs

Conflicts:
	plugins/system/debug/debug.php
Filter out empties from the categories array