correct errors in documentation

[stephengold]

This is mostly for typos in Java comments.

[capdevon]

Hi Stephen, great job as always!
There would also be the names of these two methods, in the MotionPath class, which start with a capital letter and do not follow the rules of the coding conventions of the java language.

https://github.com/jMonkeyEngine/jmonkeyengine/blob/master/jme3-core/src/main/java/com/jme3/cinematic/MotionPath.java#L148

private Geometry CreateLinearPath() { ... }

https://github.com/jMonkeyEngine/jmonkeyengine/blob/master/jme3-core/src/main/java/com/jme3/cinematic/MotionPath.java#L158

private Geometry CreateCatmullRomPath() { ... }

There should be no problem correcting them to lowercase, as the two methods are private.

[stephengold]

You're right that those 2 methods should be renamed. However, it should be a separate PR.

[capdevon]

Ok, I've opened a new issue. #1587