Do the libraries last, not first, to allow linking on 12.04.
Use gdk/gdk.h, use ~/.zterm/config, check for read errors.

Use gdk/gdk.h as the only gdk header that we include, instead of trying
to include specific gdk headers.

Switch from the old ~/.temuterm/config to ~/.zterm/config, exact same
format.

When reading the config file, check the return value of fread.
(Silents a compile time warning.)