Related: rhbz#1091111 GetSdrPageView can return NULL

Change-Id: I560bf74235728fb39156c32b47dd40f181dada16
Revert "give empty constructed default font a default height"

and make a real copy of the TargetFont

the 0,0 font size appears to mean "default" size so it can
take the desktop env font size or some such, with a hard-coded
value then the various "bold" entries in the UI are huge

This reverts commit 121aac37673c1a8142db01e26e50be6de7b36987.

Change-Id: Iec1d3867403808370d89d6b5ad2fec60ffdcd881