Cleanup: Remove extra glFlush calls from a few places.

glFlush may make the program wait until the GL driver has forwarded all commands to the GPU. glFlush is already called once in the main loop just before swapping buffers and checking for user input.

albow/tab_panel.py

@@ -214,6 +214,5 @@ class TabPanel(Widget):
             glDrawPixels(self.width, self.height,
                 GL_RGBA, GL_UNSIGNED_BYTE, fromstring(data, dtype='uint8'))
             glPopAttrib()
-            glFlush()
 
             glDisable(GL_BLEND)

albow/widget.py

@@ -750,7 +750,6 @@ class Widget(object):
             GL.glDrawPixels(self.width, self.height,
                 GL.GL_RGBA, GL.GL_UNSIGNED_BYTE, fromstring(data, dtype='uint8'))
             GL.glPopAttrib()
-            GL.glFlush()
 
     def gl_draw_self(self, root, offset):
         pass