refs #8614 Should fix the issue.

Though careful checks are needed. (and system tests as well)
refs #8614 temporary reverted changes

as they cause strange behaviour

Revert "refs #8614 Should fix the issue."

This reverts commit a41f3e45c2a0abbe6a1c9f93f9a26d6140265ad8.
refs #4614 here the changes brought back again
refs #8614 trying to nail down reason for MARI tests failing
refs #8614 Now it works as expected for LET

and changed LET_Parameters.xml to have default nexus files to be nexus, not event nexus files.
refs #8614 Minor comments
refs #8614 Removed unnecessary parameter in instrument definition file

Generic loader now distinguish between nexus and event nexus file.
Merge branch 'master' into bugfix/8614_letReduction
refs #8614 Dealing with consequences of ill defined merge

Some code pieces came not valid
Refs #8020. Change loading code to use temporary workspace.

Temporary workspace is not in the ADS. When loading/correction/grouping
are finished - temporary workspace is added to the ADS replacing
MuonAnalysis and MuonAnalysisGrouped.
Refs #8020. Remove redundant method.

We do not delete ranged workspaces as we are no longer storing them
in the ADS.
Refs #8020. Re-enable support for a range of workspaces.
Refs #8020. Fix DTC of multi-period workspaces.
Refs #8020. Fix problem with groups not being replaced correctly.

ADS::addOrReplace is not replacing groups properly, which clutters up
ADS quite badly.
Refs #8020. Fix groupWorkspace() to handle ws which are already in ADS
Refs #8020. Make it possible to load after loading error.
Refs #8020. Add another version of groupWorkspace.

Previous version was trying to determine whether workspace is already
in the ADS. It seems more natural to have two version of the function:
one for when we need to group workspace which is already in the ADS
and one to group newly created workspace.
Re #8359. Eliminate memory leaks in MRUList test.

It is the caller's responsibility to delete objects being dropped from the
MRU list, and that wasn't being done here before.
Re #8359. deleteIndex needs to also delete the pointed-to object.

I think. Certainly, this removes a memory leak in the MRUList unit test.
I will have to be guided by the other tests (including the system tests)
as to whether this is always the right thing to do. The method is only
directly used by the EventWorkspaceMRU class.
Re #8359. Clean up MRUList for readability.

Use auto to avoid long-winded declarations and remove unneeded local
variables and headers.