FS#13972 - Improve rbutil SAPI5 stability (Alessio Lenzi)

The existing code treated any ready-read notification from cscript as
proof that synthesis had completed. The SAPI script can emit other
output, so the Utility could check for the wave file before the explicit
SYNC reply and report that the output file did not exist.

The script also used global "On Error Resume Next" without reporting
errors from SpFileStream.Open(), SpVoice.Speak(), or
SpFileStream.Close(). Several waits had no timeout, allowing the GUI
thread to remain blocked indefinitely.

The changes:

 * reports SAPI COM errors to Rockbox Utility;
 * verifies that SAPI actually created the requested wave file;
 * waits for the explicit SYNC reply instead of any process output;
 * applies finite timeouts to vendor queries, synthesis, and shutdown;
 * terminates a stuck private cscript process safely;
 * restarts cscript and retries the current string up to three times when a
   third-party SAPI engine stops responding during a long generation run.

Change-Id: I2cf2aefb704353c648bef0c4312f35282ac4e25d

tools/sapi_voice.vbs

@@ -46,6 +46,7 @@ Dim oVoice ' for traversing the list of voices
 Dim nLangID, sSelectString
 
 Dim aLine, aData    ' used in command reading
+Dim nError, sError  ' error returned to the controlling process
 
 On Error Resume Next
 
@@ -146,10 +147,27 @@ Do
             aData = Split(aLine(1), vbTab, 2)
             If bVerbose Then WScript.StdErr.WriteLine "Saying " & aData(1) _
                                                       & " in " & aData(0)
+            Err.Clear
             oSpFS.Open aData(0), SSFMCreateForWrite, false
-            Set oSpVoice.AudioOutputStream = oSpFS
-            oSpVoice.Speak aData(1)
-            oSpFS.Close
+            nError = Err.Number
+            sError = Err.Description
+            If nError = 0 Then
+                Set oSpVoice.AudioOutputStream = oSpFS
+                oSpVoice.Speak aData(1)
+                nError = Err.Number
+                sError = Err.Description
+                oSpFS.Close
+                If nError = 0 And Err.Number <> 0 Then
+                    nError = Err.Number
+                    sError = Err.Description
+                End If
+            End If
+            If nError <> 0 Then
+                oStdOut.WriteLine "ERROR" & vbTab & nError & ": " & sError
+                Err.Clear
+            ElseIf Not oFSO.FileExists(aData(0)) Then
+                oStdOut.WriteLine "ERROR" & vbTab & "SAPI reported success but created no wave file"
+            End If
         Case "EXEC"
             If bVerbose Then WScript.StdErr.WriteLine "> " & aLine(1)
             oShell.Run aLine(1), 0, true