Cleanups for utilities

[javagl]

So this is somewhat experimental (maybe not to be merged). It addresses #252 and (to some extent) #253 .

The first commit is only formatting. (I just picked the first PHP formatter that I found. I think that automatic formatting can be important, but don't give a ... care about what the exact formatting is).

The next commits are fixing the typos from #252

Two commits are for some minor formatting of the license texts, and ee82cb7 adds a text to the "Stanford" license file, which until now, only contained
"See the page on ...tbd."
But... I think that this file is not actually used. Maybe it could simply be removed (similarly for some other files in the LICENSES folder)

In the last commit, I tried to fix the license links that didn't lead anywhere, but should have led to the LICENSES folder. There, I stumbled a bit. I'll have to read the PHP more thoroughly (and in the course of that, I'd probably add comments!!!). It looks like there are two ways about how this can be run, and one of them inserts some licenseUrl into the metadata.json, unless that licenseUrl was already there. Even without a deeper understanding of what the PHP is doing exactly: I think that it should NOT modify the metadata.json, ever. This is supposed to be pure input. It can be checked and validated and the CI can fail when it's not complete and whatnot. But it should NOT be modified by CI.

[javagl]

Now I wonder whether there's an easy way to ~"trigger a rebuild, and see what the repo would look like after these changes". Have to spend more time for all that...

[lexaknyazev]

Could the scripts check that "spdx" values in metadata.json files are correct to prevent cases like #227?