gdb: UnoReferencePrinter: prevent ambiguity problems
gdb: UnoReferencePrinter: prevent ambiguity problems

gdb 7.5.1 complains about ambiguous base class "XInterface" with cast()
so try dynamic_cast() instead.

Change-Id: I99a21eea7251e663deee395f6a13ca0ed041e8c9

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core