Fix bug where post slugs/permalinks used old structure.

git-svn-id: https://plugins.svn.wordpress.org/wp-seedbank/trunk@749081 b8457f37-d9ea-0310-8a92-e5e31aec5664
Version bump to 0.2.2; update change log with bugfix info.

git-svn-id: https://plugins.svn.wordpress.org/wp-seedbank/trunk@749082 b8457f37-d9ea-0310-8a92-e5e31aec5664