improve the TransformTrack javadoc (jMonkeyEngine#1642)

* TransformTrack:  don't imply that the target must be a bone

* TransformTrack:  don't imply that the track must be a joint track

* TransformTrack:  delete mentions of "this track" from the javadoc

* TransformTrack:  do getters return internal arrays or copies?

* TransformTrack:  consistent verb forms and better grammar in javadoc

* TransformTrack:  no need to mention that "times" is a float array

* TransformTrack:  mention that setTimes() creates an alias

* TransformTrack:  document arguments that can be null

* TransformTrack:  clearer descriptions of the class and its fields

* "frame" -> "keyframe", in case it's unclear they're the same thing

* document where argument length must be the same as times.length

* TransformTrack:  summary fragments shouldn't form a complete sentence

* TransformTrack:  capitalize and punctuate the summary fragments

* TransformTrack:  indent block-tag continuation lines

Test and solution for issue jMonkeyEngine#1564 (setting Material para…

…meter of type IntArray) (jMonkeyEngine#1565)

* Fixes IntArray material parameters (jMonkeyEngine#1564)

* Improved array parameter handling in Uniforms (jMonkeyEngine#1564)

* Added UnifortTest (jMonkeyEngine#1564)

Matrix4f: improve the javadoc (jMonkeyEngine#1550)

* Matrix4f: improve javadoc (1st pass)

* Matrix4f: improve javadoc (2nd pass)

correct the dependencies of jme3-jbullet (jMonkeyEngine#1541)

* jme3-jbullet: upgrade vecmath to v1.5.2

* delete jbullet.jar & stack-alloc.jar, get them from MavenCentral instead

GLRenderer: avoid NPE reported by Pavl_G (jMonkeyEngine#1527)

main.yml: limit continuous integration to recent release branches

JoystickCompatibilityMappings: @author can't be used in method javadoc

fix issue jMonkeyEngine#1496 2nd try (Android natives missing from JARs)

fix issue jMonkeyEngine#1496 (Android natives missing from JARs at Ma…

…venCentral)

Added profile tracking to AppStateManager for render and post render. (…

…jMonkeyEngine#1485)