Reverted to manual construction of body parameter for wp_remote_post() to allow checkboxes to work.

git-svn-id: https://plugins.svn.wordpress.org/wpgform/trunk@842811 b8457f37-d9ea-0310-8a92-e5e31aec5664
Prep for v0.64 release.

git-svn-id: https://plugins.svn.wordpress.org/wpgform/trunk@842812 b8457f37-d9ea-0310-8a92-e5e31aec5664