Jetpack: WPCC: Updates to functionality after chat with @lessbloat.  Dropping some options for the user to make, but migrating them to constants they can define in wp-config, as it's more a security-based choice.  Updating strings.

git-svn-id: https://plugins.svn.wordpress.org/jetpack/trunk@757472 b8457f37-d9ea-0310-8a92-e5e31aec5664