Add animated transitions to Kiwi.

This adds two class hierarchies to kiwi:
`vesKiwiTransition` and `vesKiwiEasing`.
Together, they implement animated transitions.
The Kiwi application's reset view button uses
the camera transition to smoothly reorient the
camera to the initial view provided by a kiwi
scene file.

This also expands on and documents the shared
pointer macros available to all ves classes.
A tutorial for using transitions.
Eliminate warning.
Add withTransitions argument to resetView() calls.
Eliminate warning.
Fix `alsoStart()` and `followedBy()` transitions.

They should return the current transition, not the chained one.
Otherwise, only the last transition will get queued.
Use `vesVector4f` to store color in `vesMapper`.

This is useful for animating colors since `vesVector4f`
provides scalar multiplication and vector addition operators.
Small API changes for animated transitions.

... to allow opacity and color to be animated.
A transition for altering member variable values.

Any class that provides
1. methods to get/set member variables using the specified signatures and
2. whose type provides scalar multiplication and vector addition
can be transitioned with this class.
An example of vesKiwiIVarTransition...

... but not exercised during testing yet.
Fix a cut-and-paste-o.
Add `withTransitions` to Android `resetView` method.
Respond to review from Aashish, Casey.
Address more review comments from Casey.
Style and documentation changes.
Properly JNI-wrap modified resetView() method.

This adds a method to obtain active transitions from the
application so that the Android app can decide when to
render (or not).
Add an "easter egg" to TestGradientBackground.

Press the 'h' key to make the bunny hop and fade
through Easter colors.
Merge topic 'animated-transitions'

e2126b2 Add an "easter egg" to TestGradientBackground.
14e3958 Properly JNI-wrap modified resetView() method.
d81e8cd Style and documentation changes.
6a4555f Address more review comments from Casey.
094bd5a Respond to review from Aashish, Casey.
3148fa2 Add `withTransitions` to Android `resetView` method.
ed2ec3f Fix a cut-and-paste-o.
da54dea An example of vesKiwiIVarTransition...
a254263 A transition for altering member variable values.
aabd863 Small API changes for animated transitions.
717e3db Use `vesVector4f` to store color in `vesMapper`.
be598ce Fix `alsoStart()` and `followedBy()` transitions.
7bf1418 Eliminate warning.
7ce8014 Add withTransitions argument to resetView() calls.
7cad417 Eliminate warning.
d79a48e A tutorial for using transitions.
...