This will help ensure that for the system tests we can reset the config
once it has loaded and only save keys that we change just in case an old
config was not restored.

Also add a couple more that were missing and re-order so that the list
is in the same order as they appear in the properties file. Re #5249.

It should point to the sub-directory.

The relative path was wrong for OS X. It now just uses the key in
the properties file. Also quietened the output of querying paraview
by capturing the stderr as well.

It did call -V which ends up starting a GUI briefly and is quite slow on
OS X. Changed to --help as this is faster and we don't grab anything from
the version string anyway.

Changes required so that the final bundle has the correct library links to
ParaView in the pvplugins.

Eliminates an exception on Windows when setting user preferences.

Move PVPLUGINS to a subdirectory of PVPLUGINS. This has two advantages. Firstly it maintains the possiblity to keep the loading of PV related mantid components separate from those in Mantid Plugins. Secondly it means that Paraview standalone does not crash when PV_PLUGIN_PATH is used. Only Paraview plugins sit in the subdirectory, so the Paraview loader doesnt get confused by the presence of these other libraries

Make it possible to ignore Paraview dependent components completely ad continously if required.

Cleaned out a load of older checking code. Separately load up pv_plugins from normal plugins if paraview is present.

The old api had lowercase 'i' for the facility.instruments but the C++
has uppercase. Lowercase follows our style so the C++ has been changed
so that the new can follow this.

The framework should be mostly clear of cppcheck errors now.

In the case where a user wishes to load a file with a name which is not of the
"standard" format (including a valid instrument), our call to the
ConfigService getInstrument method should not report an error.

A debug message is sufficient, and there is still an exception thrown which
a class user can then interpret in any way he/she sees fit.

When running mantid you know where the plugins are supposed to exist relative to
the MantidPlot executable. Just set the environment variable.

Minor fix for the default save directory being appended to the data search path mutiple times when it does not contain a slash at the end. Refs #3874