Duplicate print statements to the console as well

The capture of print statements to the message display is useful, but
makes debuging crashes difficult because the message display disappears
before anything can be read. The solution is to write the print
statements to both places.

qt/applications/workbench/workbench/plugins/logmessagedisplay.py

@@ -29,6 +29,8 @@ from workbench.plugins.base import PluginWidget
 
 # Default logs at notice
 DEFAULT_LOG_PRIORITY = 5
+ORIGINAL_STDOUT = sys.stdout
+ORIGINAL_STDERR = sys.stderr
 
 
 class LogMessageDisplay(PluginWidget):
@@ -44,10 +46,10 @@ class LogMessageDisplay(PluginWidget):
         self.setWindowTitle(self.get_plugin_title())
 
         # output capture
-        stdout_capture, stderr_capture = WriteToSignal(), WriteToSignal()
-        stdout_capture.sig_write_received.connect(self.display.appendNotice)
-        stderr_capture.sig_write_received.connect(self.display.appendError)
-        self.stdout, self.stderr = stdout_capture, stderr_capture
+        self.stdout = WriteToSignal(ORIGINAL_STDOUT)
+        self.stdout.sig_write_received.connect(self.display.appendNotice)
+        self.stderr = WriteToSignal(ORIGINAL_STDERR)
+        self.stderr.sig_write_received.connect(self.display.appendError)
 
     def get_plugin_title(self):
         return "Messages"

qt/python/mantidqt/utils/test/test_writetosignal.py

@@ -18,6 +18,7 @@ from __future__ import (absolute_import)
 
 # std imports
 import unittest
+import sys
 
 # 3rdparty
 from qtpy.QtCore import QCoreApplication, QObject
@@ -38,7 +39,7 @@ class WriteToSignalTest(GuiTest):
 
     def test_connected_receiver_receives_text(self):
         recv = Receiver()
-        writer = WriteToSignal()
+        writer = WriteToSignal(sys.stdout)
         writer.sig_write_received.connect(recv.capture_text)
         txt = "I expect to see this"
         writer.write(txt)

qt/python/mantidqt/utils/writetosignal.py

@@ -27,6 +27,9 @@ class WriteToSignal(QObject):
     used to transform write requests to
     Qt-signals. Mainly used to communicate
     stdout/stderr across threads"""
+    def __init__(self, original_out):
+        QObject.__init__(self)
+        self.__original_out = original_out
 
     sig_write_received = Signal(str)
 
@@ -40,4 +43,7 @@ class WriteToSignal(QObject):
         return False
 
     def write(self, txt):
+        # write to the console
+        self.__original_out.write(txt)
+        # emit the signal which will write to logging
         self.sig_write_received.emit(txt)