goffice0.10: update to 0.10.48

goffice 0.10.48:

Jean:
* Avoid serializing empty graph data. [#46]
* Clip data labels in XY plots. [#47]
* Don't emit a critical for invalid series in Logarithmic fit. [#49]
* Optimize GtkWidget embedding in the canvas. See #465.
* Clip grid lines rendering to the plot area. [#50]
* Speed up GocGroup for large number of children.  [Gnumeric #465]
* Make GocGroup usable as a widgetless canvas.

Morten:
* Avoid critical in document image handling.
* Introspection fixes.
* Speed up GocGroup for large number of children.  [Gnumeric #465]
* Stop checking for Xrender.
* Plug leaks.

(nia)