* Make OK button the default action in the 3D viewer option dialog per UI
policy.
* Fix standard button sizer padding in 3D viewer options dialog.
* Let sizers do their job by using default size for 3D viewer options
dialog.
* Set 3D viewer hot key to Alt+3 in all parent windows where 3D viewer is
accessible.
* Minor code cleaning and coding policy fixes.
File "rules" has instructional text as comments near top.
2) Convert all text files in repo to LF line ending form.
Any checkout done with "rules" in play will convert the working
tree to native line ending, while keeping repo as LF line ending.