Added support for all hierarchical post types

Displays meta box on any hierarchical post type
Patch for bug where exclude status doesn't save

Removed ep_set_option() function and replaced with  update_option()
from WP core. It is not necessary to delete, then re-add the option
because update_option() will update with new value if an option exists,
and create it if it does not.  This prevents the bug where if the
option does not get deleted for some reason, the new value will not get
saved.
Improvements to ep_update_exclusions()

Added code to prevent saving on auto-save, a check to be sure the
person updating the value has the rights to do so, and a check to
prevent saving the post revision IDs to the excluded pages array.
Previously it saved both the primary post ID and the ID of the
revision. This will cut the size of the excluded pages array by at
least 50%.