Update paypal_transaction post type arguments

[diedexx]

The paypal_transaction post type is being registered with a lot of arguments. Arguments which aren't necessary because their default values are the same, or their default or other values fit the post type better.

I've changed the following

argument	old value	new value	reason
show_ui	false	false (default)	default value is the same
capability_type	'post'	'post' (default)	default value is the same
capabilities	array( 'create_posts' => false)	array() (default)	Its value doesn't seem to matter in the case of paypal_transactions. Just leave it as its default value
map_meta_cap	true	null (default) which translates to true	default value is the same
publicly_queryable	true	false (default)	Transactions should not be publicly accessible
exclude_from_search	false	false (default)	default value is the same
hierarchical	false	false (default)	default value is the same
rewrite	array('slug' => 'paypal_ip')	true (default)	Its value doesn't seem to matter in the case of paypal_transactions. Just leave it as its default value
query_var	true	false	Transactions should not be publicly accessible
supports	array('', '')	array() (default) which translates to ( 'title', 'editor' )	Its value doesn't seem to matter in the case of paypal_transactions. Just leave it as its default value
has_archive	true	false (default)	Transactions should not be publicly accessible, and thus shouldn't have an archive
show_in_nav_menus	FALSE	false (default)	default value is the same

[angelleye]

@diedexx thanks for the feedback and the commit! We'll review and include in our 1.4.9 update coming soon. Thanks!