Added loop feature to hide and show animations

[Cristiano-Maggi]

I added the loop to hide and show. It works the same way as it works for transformations now, there's a field in the UI for entering the loop value and the line ANIM_keyframe_loop is exported followed by the entered value.
2 things I don't know how to do though:

1. The line is exported as (example) ANIM_keyframe_loop 2 and not ANIM_keyframe_loop 2.0
2. The line is exported only once even if 2 or more hide are added to the same mesh. Example: I need to hide the same mesh at two different time intervals for animating the flags but both the hide would need their own loop and not just a loop after the two hide calls.

See how it is exported and how I would like it to be in these screenshots.

[bsupnik]

@Cristiano-Maggi can you please attach a small .blend file that reproduces this issue (E.g. two "stacked" show-hides where only one loops?). Thanks!

[Cristiano-Maggi]

Sure @bsupnik ! Here you are

Loop_Example.blend.zip