Fix unclosed Cursors

When investigating an `android.database.CursorWindowAllocationException` crash, I came across [this StackOverflow post](http://stackoverflow.com/questions/21219039/android-database-cursorwindowallocationexception-when-moving-a-cursor) which suggests that they're caused by unclosed `Cursor`s. I took a look through CBL and found two that weren't being closed.