Add egs_dynamic_geometry and egs_view time viewing

[a-l-demelo]

Add the ability for dynamic geometries, including translation and rotation of any geometry. This is similar to egs_dynamic_source. Time indices are synchronized with any source that includes time indexes such as egs_beam_source, IAEAphsp_source, and egs_dynamic_source.

Add a time slider to egs_view that shows geometry motion. Includes a time window for showing tracks over a window of time, and the tracks update as you move the time index slider to show tracks synchronized with geometry motion.

[blakewalters]

This is excellent! I tested out dynamic motion of a fairly complex rotating geometry within a stationary one (I also threw in some translation for good measure), and I was able to display the track evolution in egs_view beautifully. I would just clarify the documentation at the top of the egs_dynamic_geometry.h a bit by:

1. changing the notation for the translation from "x(N) y(N) z(N)" to "xtransl(N) ytransl(N) ztransl(N)"
2. indicating that rotations are defined in degrees and translations in cm. Otherwise, let's get this merged forthwith!

[ftessier]

@a-l-demelo if you have time please comment on the review comments. In the meantime I will address the minor issues.