- Name changed stresstesting.MantidStressTest -> systemtesting.MantidSystemTest
- Update the dev-docs as well

Re #0

Update copyright headers in all files

Squashed commit of the following:

* First version of a script to manage copyright statements

re #23468

* Neatened up script, added comments

re #23488

* move script to tools directory

re #23488

* small script changes and a couple of manual file changes

re #23488

* Minor chnage to whitespace detection in regex

re #23488

* Add an excluded directory

re #23488

* remove a repeasted copyright statement in a file

re #23488

* Don't comsume the comment end if it is on the same line

re #23488

* fix error in new copright parsing

re #23488

* remove double copyrifght entry

re #23488

* Improve handling of old copyrights at the start of comments

re #23488

* remove empty comments re #23488

* exclude gsoapgenerated directories

re #23488

* Sort out greedy line matching re #23488

* improve empty comment removal

re #23488

* improve false positives

re #23488

* impressive speedup by limiting regex matching length

re #23488

* remove evil invisible non ascii character

Also upadte the copyright at the same time

re #23488

* resolve multiple copyrights in a single file

re #23488

* resolve an issue with new statement detection

re #23488

* another unprintable unicode character

re #23488

* pep updates and cmake the new copyright fit clang format

re #23488

* update already done new format headers

re #23488

* wrong type of bracket

re #23488

* Update class_maker and friends

re #23488

* Update all copyright statements

re #23488

* clang format re #23488

* flake8 warnings re #23488

* Flake8 warnings re #23488

* Exclude .cmake.in and rb.in files

re #23488

* replace missing line re #23488

* exclude .py.in files as they are flasely recognized as C++

re #23488

* another setp.py.in re #23488

* another .py.in correction re #23488

* Hopefully the last of the .py.in files re #23488

* resolve utf-8 encoding of python files and changed ABINS checksum

re #23488

* updates to unit tests that reference line numbers

re #23488

* remaining unit test files and other fixes

re #23488

Found via `codespell -q 3 -I ../mantid-word-whitelist.txt` where whitelist consists of  
```
alloced
allws
amin
ang
ans
arithmetics
dum
focussed
dur
iff
isnt
ith
lod
minimise
mut
mye
nd
originaly
realy
sav
splitted
te
tim
uint
vertexes
```

A master test list is first built from scanning the test python files.
For each module in this list, a list of data files required by that
module is created. An accompanying lock status for each data file is
also created.

Each thread then starts a loop and gathers a first test module from the
master test list which is stored in the tests_dict shared dictionary,
starting with the number in the module list equal to the process id.

Each process then checks if all the data files requird by the current
test module are available (i.e. have not been locked by another
thread). If all files are unlocked, the thread proceeds with that test
module. If not, it goes further down the list until it finds a module
whose files are all available.

Once it has completed the work in the current module, it checks if the
number of modules that remains to be executed is greater than 0. If
there is some work left to do, the thread finds the next module that
still has not been executed (searches through the tests_lock array
and finds the next element that has a 0 value).

This aims to have all threads end calculation approximately at the
same time, and also avoids having to modify many save directories
in the test files and the facilities interfaces they use.