the_loops() instead of $the_loops

Uses now the_loops() instead of the global $the_loops (same instance
system than bbPress).
clean up

cleaned up comments & coding standards
replaced global $post_ID by get_the_ID()
added default for function tl_get_loop_parameters()

if no parameter is set for function tl_get_loop_parameters(), use
get_the_ID() as default.
cleaned up globals

use variables from class instead.
!BUG FIX!! use a fallback template

Use a fallback template when a loop try to load a template file which
do not exists (anymore) - or the plugin will crash.
commit bug fixes

some fixes for the previous commits.