LoadInstrumentFromRaw modified to clear any existing instrument instance from...

LoadInstrumentFromRaw modified to clear any existing instrument instance from the workspace before getting to work. Necessary since this algorithm is called when LoadInstrument fails, which can happen when a partial Instrument is loaded, leading to confusion. Re #703.

Code/Mantid/DataHandling/src/LoadInstrumentFromRaw.cpp

@@ -61,6 +61,10 @@ void LoadInstrumentFromRaw::exec()
     g_log.error("Unable to open file " + m_filename);
     throw Exception::FileError("Unable to open File:" , m_filename);
   }
+
+  // Clear off any existing instrument for this workspace
+  localWorkspace->setInstrument(boost::shared_ptr<Instrument>(new Instrument));
+
   // Get reference to Instrument and set its name
   boost::shared_ptr<API::Instrument> instrument = localWorkspace->getBaseInstrument();
   if (instrument.get() == 0)