include PySide in qt4agg backend check

setup.py

@@ -93,7 +93,6 @@
     setupext.BackendMacOSX(),
     setupext.BackendQt5(),
     setupext.BackendQt4(),
-    setupext.BackendPySide(),
     setupext.BackendGtk3Agg(),
     setupext.BackendGtk3Cairo(),
     setupext.BackendGtkAgg(),

setupext.py

@@ -1958,7 +1958,18 @@ def check_requirements(self):
         return msg
 
 
-def backend_qt4_internal_check(self):
+def backend_pyside_internal_check(self):
+    try:
+        from PySide import __version__
+        from PySide import QtCore
+    except ImportError:
+        raise CheckFailed("PySide not found")
+    else:
+        BackendAgg.force = True
+        return ("Qt: %s, PySide: %s" %
+                (QtCore.__version__, __version__))
+
+def backend_pyqt4_internal_check(self):
     try:
         from PyQt4 import QtCore
     except ImportError:
@@ -1973,6 +1984,25 @@ def backend_qt4_internal_check(self):
         BackendAgg.force = True
         return ("Qt: %s, PyQt: %s" % (self.convert_qt_version(qt_version), pyqt_version_str))
 
+def backend_qt4_internal_check(self):
+    try:
+        result1 = backend_pyside_internal_check(self)
+    except CheckFailed:
+        result1 = None
+
+    try:
+        result2 = backend_pyqt4_internal_check(self)
+    except CheckFailed:
+        if result1 == None:
+            raise
+        result2 = None
+
+    if result1 == None:
+        return result2
+    if result2 == None:
+        return result1
+    return '{}; {}'.format(result1, result2)
+
 
 class BackendQt4(BackendQtBase):
     name = "qt4agg"
@@ -2006,27 +2036,6 @@ def __init__(self, *args, **kwargs):
         self.callback = backend_qt5_internal_check
 
 
-def backend_pyside_internal_check(self):
-    try:
-        from PySide import __version__
-        from PySide import QtCore
-    except ImportError:
-        raise CheckFailed("PySide not found")
-    else:
-        BackendAgg.force = True
-        return ("Qt: %s, PySide: %s" %
-                (QtCore.__version__, __version__))
-
-
-class BackendPySide(BackendQtBase):
-    name = "pyside"
-
-    def __init__(self, *args, **kwargs):
-        BackendQtBase.__init__(self, *args, **kwargs)
-        self.callback = backend_pyside_internal_check
-
-
-
 class BackendCairo(OptionalBackendPackage):
     name = "cairo"