If we cannot write to user configuration directory, then write
the logs to the systems temp directory.

refs #7959

The SettingsTest.py is python api version 1. In version 2, the
welcomeMessage function is no longer exposed to python

The package build throws this warning with the PythonAlgs directory.

Refs #970

Thisgs to note:
 * C2450 warnings have been suppressed when including Poco headers
   that inherit from std::stream
 * Boost date_time no longer accepts just a date for an ISO date/time
   string

The MPI build no longer logs to file by default (as this duplicates
the console channel which ends up in a log file for a job).

The format of log messages to the console has been changed to include
hostname & process id so that messages can be separated
according to which mpi rank they relate to. The rank is explicitly
logged at startup.

This works, but needs a little refactoring to improve readability.

The fermi cluster at ORNL uses the usual SNS home areas (so the same
as the analysis workstations, for example). If the user properties
file is the same, confusion could arise if things are set in it
in and interactive MantidPlot session.
The MPI build now uses Mantid-mpi.user.properties instead.

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.