Makes brltty not show cofusing messages such as 'screen not in text mode'
to the user when the api client is not connected.  This is needed because
it is hard to localize those messages and they don't mean anything to
the end user.
--- a/Programs/scr_base.c
+++ b/Programs/scr_base.c
@@ -82,7 +82,7 @@
   }
 }
 
-static const char *text_BaseScreen = "no screen";
+static const char *text_BaseScreen = "";
 
 static int
 selectVirtualTerminal_BaseScreen (int vt) {
--- a/Programs/config.c	(revision 7783)
+++ b/Programs/config.c	(working copy)
@@ -1273,7 +1273,7 @@
 exitBrailleDriver (void) {
   if (brailleConstructed) {
     clearStatusCells(&brl);
-    message(NULL, gettext("BRLTTY terminated"), MSG_NODELAY|MSG_SILENT);
+    writeBrailleText("", "");
   }
 
   stopBrailleDriver();
--- a/Drivers/Screen/Linux/screen.c	(revision 7783)
+++ b/Drivers/Screen/Linux/screen.c	(working copy)
@@ -42,14 +42,16 @@
   PARM_CHARSET,
   PARM_HFB,
   PARM_DEBUGSFM,
+  PARM_MSGS,
 } ScreenParameters;
-#define SCRPARMS "charset", "hfb", "debugsfm"
+#define SCRPARMS "charset", "hfb", "debugsfm", "msgs"
 
 #include "scr_driver.h"
 #include "screen.h"
 
 static const char *problemText;
 static unsigned int debugScreenFontMap = 0;
+static unsigned int showProblemText = 1;
 
 #define UNICODE_ROW_DIRECT 0XF000
 
@@ -622,6 +624,15 @@
     }
   }
 
+  showProblemText = 1;
+  if (*parameters[PARM_MSGS]) {
+    if (!validateYesNo(&showProblemText, parameters[PARM_MSGS])) {
+      logMessage(LOG_WARNING, "%s: %s", "invalid value for msgs",
+                 parameters[PARM_MSGS]);
+      showProblemText = 1;
+    }
+  }
+
   return 1;
 }
 
@@ -1021,7 +1032,7 @@
   }
 
   description->rows = 1;
-  description->cols = strlen(problemText);
+  description->cols = showProblemText ? strlen(problemText) : 0;
   description->posx = 0;
   description->posy = 0;
   return 0;
@@ -1092,7 +1103,7 @@
   if (readScreenDimensions(&columns, &rows)) {
     if (validateScreenBox(box, columns, rows)) {
       if (problemText) {
-        setScreenMessage(box, buffer, problemText);
+        setScreenMessage(box, buffer, showProblemText ? problemText : "");
         return 1;
       }