gtk2 built

This is a patch to get a correct gtk2 build. It changes some
TOOLKIT_GTK into TOOLKIT_GTK_ALL

Also I needed to create the following link so that the compiler could
find some ".h" files:
ln -s src/text/fmt/gtk src/text/fmt/gtk2

Two other things included in the patch:

1) The build now requires redland 1.0.12 (librdf_stream_get_context2()
used in file pd_RDFQuery.cpp).
2) Some changes in ap_UnixDialog_InsertXMLID.cpp to compile with gtk
2.12 - 2.20.

Simon