1. IDS mangling used for checksum is now inst name + sha1 of xml
 1.1. sha1 is computed after converitng to linux line endings and trim
 1. VTP file names changes to be same filename as IDS mangling
 1. VTP save directory moved to appdata/mantidproject/instrument/geometryCache
 1. VTP file saving simplified as files based on a checksum cannot be out of date
 1. unit tests updated to account for this
 1. unused methods removed from IDFObject
 1. InstrumentDefinitionParser changed to initialise during constructor
 1. XML parsing changed to lazy load rather than during initialisation.

Still to do:
 1. cache SHA1 checksum if needed
 1. Change the filename reported for nexus files
 1. Manually test
 1. Stop saving the filename to nexus files
 1. update documentation

re #11818

It is still backwards compatible with the old log-entry format.
Refs #11359

Added a legacy file as well as a new style peaks workspace nxs format file. The same loader handles both.
Added 'unit tests' for both.

size_t is converted to uint64_t on saving to nexus.

Extend tests. Do not process spectrum lists.

Also better robustness around workspace type.

We are not currently handling log extraction properly, which is why the test is failing.

File size is just over the threshold, but shouldn't be a problem. I've tried to trim it down as much as possible.

Fails right now because of the extra whitespace at the end of entries
in the string column.

Refs #7764

Names will attempt to match with a stem on load.
If not the stored name will be used.

Backwards compatible with older nexus files.

Refs #7764

Signed-off-by: Karl Palmen <karl.palmen@stfc.ac.uk>

The leak was due to the workspace history exponentially increasing
in size. This history was duplicated with each run and then one algorithm
added. The history is now in a set and only those algorithms that have not
been run before are added.

Add pointer to physical instrument as a member (not used in vast majority of cases) of Instrument. Show this 'physical instrument' in the instrument view, if it exists. Re #1944.
P.S. This again lead to a const change which accounts for most of the changes.

Eradicate IInstrument. Instrument's the one to talk to now (it was the only descendent class anyway). Re #2041.

Try to fix Mac test failures. Looks to be code in the destructor of another test causing the problem. Re #3302.