Improve Documentation aroung Cloning workspaces in Python

[Owen Arnold]

Improve the documentation of what = means in Python for Mantid workspaces, both for the loose linkage between ws names and variable names, having more than one variable pointing to a workspace, and how to create a copy of a workspace. Don't forget that

a = b.clone() 

is now implemented.

This should be done as a page in the Mantid in Python training course so we can refer people to it easily.

This is the original request, but it is not what we are going to go with as the two meanings of = would be event more confusing.

Request by Tim Charlton.

He would like uses to be given a way to Clone a workspace upon equals as though it was a separate workspace rather than working on a reference. This is specifically for python users.

For example. currently in the following A and B reference the same workspace:

A = B

However the behaviour requested is that:

A = B

is analogous to:

A = CloneWorkspace(B)

[Owen Arnold]

refs #10034. Add doc tests and description

This algorithm was completely missing any usage examples. Description has also been updated. Included quite a large discussion on alias vs copy in python as well as some examples.

Changeset: c2cb4b233c66fcfee93ce1613d2ccf5678dc4677

[Martyn Gigg]

There is a sphinx warning in CloneWorkspace-v1.rst: ​http://builds.mantidproject.org/view/Develop%20Builds/job/develop_clean/label=win7-build/311/warnings3Result/

[Owen Arnold]

refs #10034. Fix underline issue.

Changeset: 48ed45b5e15bf0dac18b2cbae6f3a3b6720afc17

[Nick Draper]

Moved to the backlog at the code freeze of R3.3

[Stuart Campbell]

This ticket has been transferred to github issue ​10876