I've uploaded a release candidate for the shortly forthcoming 2.2.0 release. The major change here is the addition of some new methods to QPDFObjectHandle that allow creation of new streams and replacement of data for existing streams. There is also new convenience routines for manipulating dictionary keys and for working with a page's content streams. I intend to release 2.2.0 within the next week or two. Please note that 2.2.rc1 is not the default download, so you have to download it explicitly if you want to try it out.