First attempt at making wp_editors in loops more reliable
Changes:
-wp_editor is now always used to echo the HTML regardless of whether it is
inside a loop or not (better forward compatibility)
-wp_editors in the copy template are removed on page load and readded to
the copied group after copying, instead of the old way which removed and
readded the editors each time (better performance).
-QTags is now used to readd the html editor after copying (better forward
compatibility)
-Removed the old switchTo hack due to getting QTags to work

Other changes:
-Changed various class names to be more consistent (WILL break older
templates)
-The copy template group no longer has the "last" class
-is_last() now returns false for the template group and true for the last
non-template group.
-new is_template() function to detect the template group (replaces the
above behaviour)