Re #5939. Run mantidplotrc on IPython startup.

This is in place of importing the individual mantid & mantidplot
modules and means that code completion in the 'F3 script window'
still works.

Code/Mantid/MantidPlot/ipython_widget/mantid_ipython_widget.py

@@ -12,10 +12,15 @@ def __init__(self, *args, **kw):
         kernel = kernel_manager.kernel
         kernel.gui = 'qt4'
 
-        import mantidplot
-        kernel.shell.push(mantidplot.__dict__)
-        import mantid.simpleapi
-        kernel.shell.push(mantid.simpleapi.__dict__)
+        # Figure out the full path to the mantidplotrc.py file and then %run it
+        from os import path
+        mantidplotpath = path.split(path.dirname(__file__))[0]
+        if not mantidplotpath:
+            # If the the file is in the cwd, then path.dirname returns an empty string
+            mantidplotrc = 'mantidplotrc.py'
+        else:
+            mantidplotrc = mantidplotpath + '/mantidplotrc.py'
+        kernel.shell.run_line_magic('run',mantidplotrc)
 
         kernel_client = kernel_manager.client()
         kernel_client.start_channels()