Make text appear in GUI console, Zip install works.

Move TW zip install code to C++ so that it can use the
ui->functions.
Bring in mincrypt code to fix a crash during signature
checking.
diff --git a/gui/gui.h b/gui/gui.h
index f6745d7..948e11b 100644
--- a/gui/gui.h
+++ b/gui/gui.h
@@ -5,6 +5,8 @@
 int gui_init();
 int gui_loadResources();
 int gui_start();
+void gui_print(const char *fmt, ...);
+void gui_print_overwrite(const char *fmt, ...);
 
 #endif  // _GUI_HEADER