title: libgcc_s_sjlj-1.dll is missing in Qt 5.1
body: <p>My program won't start, complaining that libgcc_s_sjlj-1.dll is needed. However, this file doesn't exist in Qt directory. I did some search and found that -static-libgcc and -static-libstdc++ should be added. So here is my .pro file:</p>
  
  <pre><code>QT       += core gui xml
  
  greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
  
  TARGET = mouseEventProcess
  TEMPLATE = app
  
  
  SOURCES += main.cpp\
          mainwindow.cpp \
      fileOp.cpp \
      xmlpraser.cpp \
      pixmapOp.cpp \
      mathOp.cpp
  
  HEADERS  += mainwindow.h \
      fileOp.h \
      xmlpraser.h \
      pixmapOp.h \
      mathOp.h
  
  FORMS    += mainwindow.ui
  #COMPILE LIBGCC_S_SJLJ-1.DLL AND LIBSTDC++-6.DLL INTO THE EXE FILE
  win32{
  QMAKE_LFLAGS += -static-libgcc
  QMAKE_LFLAGS += -static-libstdc++
  #BOOST LIBRARIES. CHANGE TO YOUR OWN.
  INCLUDEPATH += D:/boost_1_51_0
  #OPENCV LIBRARIES. CHANGE TO YOUR OWN.
  INCLUDEPATH += D:/opencv2.4.4/include
  INCLUDEPATH += D:/opencv2.4.4/release/install/include
  LIBS += -LD:/opencv2.4.4/release/install/lib \
      -lopencv_core244 \
      -lopencv_highgui244 \
      -lopencv_imgproc244
      #-lopencv_features2d244 \
      #-lopencv_calib3d244
  }
  unix{
  #BOOST LIBRARIES. CHANGE TO YOUR OWN.
  INCLUDEPATH += /home/panda/boost_1_51_0
  #OPENCV LIBRARIES.IF YOU COMPILED AND INSALLED
  #OPENCV FROM CMAKE &amp; MINGW, JUST LEAVE IT BE,
  #UNLESS YOU KNOW EXACTLY WHAT YOU ARE DOING.
  INCLUDEPATH += /usr/local/include/opencv
  INCLUDEPATH += /usr/local/include/opencv2
  LIBS += -lopencv_core -lopencv_imgproc -lopencv_highgui
  LIBS += -lopencv_ml -lopencv_video -lopencv_features2d
  LIBS += -lopencv_calib3d -lopencv_objdetect -lopencv_contrib
  LIBS += -lopencv_legacy -lopencv_flann
  }
  </code></pre>
  
  <p>If this works, neither libgcc_s_sjlj-1.dll and libstdc++-6.dll is needed. However, the program still needs libstdc++-6.dll before I put it into .exe folder.</p>
  
  <p>So my question is: Where can I get libgcc_s_sjlj-1.dll or is there any problem in my .pro file?</p>