Support for SnakeYaml 2.0+ (Velocity 3.5.0 and later)

[mfnalex]

Fixes #649

Since SnakeYaml 2.0, the CustomClassLoaderConstructor requires a LoaderOptions object as second parameter. This PR simply catches the NoSuchMethodError and then tries again with the new Constructor through reflection.

Works fine for me on Velocity 3.5.0-SNAPSHOT (git-e0db2566-b577)

[WouterGritter]

I would really like to see this merged, as floodgate is currently still broken on the latest Velocity(-CTD).

[Tim203]

Thanks for the reminder. I think that this PR looks good.
This will at least make Floodgate work again. I really don't have time to make the changes needed for that other PR that also makes local linking work for those new Velocity versions.

[mfnalex]

Thanks for merging. Local linking does work fine for us using this version, btw (using MySQL backend, not SQLite though as also mentioned in the other PR)