Remove trailing blanks and empty last lines from files

[mrdeep1]

This does touch a lot of files, but unlikely there will any merge issues of outstanding PRs.

[obgm]

Although not really nice to look at in some view modes, I am not sure if removing those really is worth the effort.

Regarding the empty last lines: IIRC this has something to do with $SOMETHING_ON_WINDOWS complaining when there is no newline at the end of the last line or so? But I guess you would be able to check that.

[mrdeep1]

Although not really nice to look at in some view modes, I am not sure if removing those really is worth the effort.

pre-commit picks up and fixes this things automatically, thus tidying up the code, even if there is no programatic difference.

Regarding the empty last lines: ....

When editing in Windows, this has the potential to throw up problems, so being rigorous here (no empty last lines, final line terminated correctly) helps.