Added PNG icons for nightly and unstable, used by NSIS for the package icon

The line for DELETEing the icon was also added back.

New algorithm to slice event workspaces for ISIS reflectometry

Disable Plot Result for MSD and F(Q) Fit for one spectra

Modified Systemtests to show more failures

Move V3D operators to be inline

It was only writing the full log to console if the test status contained 'fail'
which would apply to 'failed' and 'algorithm failure' but it was missing statuses
like 'hung'

Now the output is always printed unless the status is 'success' or 'skipped'

Project Recovery: Handle multiple instances of mantid properly

Force progress messages to be str

Add new algorithm MatchSpectra

Mantidplot/ Testing/ buildconfig/ misc. typos

The problem was that empty progress messages were being converted to
`None` which `AlgorithmObserver` did not have the proper overloaded
methods to convert to an empty string. The fix is to convert them to a
string before calling the binding. For extra measure, the progress
percentage is converted to a float as well.

Refs #23632

Refs #21800

Pete Peterson authored 6 years ago and WHITFIELDRE email committed 6 years ago

* Ignore syntax errors on startup

There was an uncaught exception in parsing the file on startup.

Refs #23555

* Invert the test that the code is executed

Refs #23555

Remove HFIR Powder Diffraction Reduction Interface

D2B normalisation fix

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
```

Move the implementation of V3D operators to the header. This results in
a significant speed up in V3D operators.

Fix errors and warnings from llvm 7.0

Update DirectILL documentation

Add adjustments to reconstructed data in Maxent

scripts: typo fixes