2.6.2:

* TreeView: When using the append_column() convenience API,
  prevent a crash when the window closes while the cell is 
  editing. Bug #170855.
* Allow derived CellRenderers to be edited, by removing 
  some debug code that sneaked into 2.6.1. Bug #172346.
* Documented many signals, based on the GTK+ documentation.
  (Murray Cumming)