Add base work for scaling and unscaling the coords

So far everything scales as expected but the size of the spheres and the
position of the camera.

A new array was added to the javascript code containing all of the
percents explained by each axis.
Change the way scaling was being performed

Refactor some scaling code to make it cleaner and remove unnecessary
code.

This should fix #5
Change camera position when scaling

The near property of the camera was set to 1, this does not depend on
the coordinates, to make zooming friendly with scaled coordinates, this
was changed to 0.1.
Fixed broken tests in test_format.py
Add changes to support the presence of ellipses

The code to scale the coordinates was not considering the case where
ellipses are present in the scene.
Fix sphere slider value when scaling coords

The value of the slider was not changed but the size of the spheres was
and when proceeding to modify the value with the slider, a glitch seemed
to appear.
Fix sphere scaling issue with slider

A new variable was added to account for the size the sphere should have
if looking at scaled coordinates the value will be the percent explained
by PC1 fi looking at unscaled coordinates the value will be 1.
Fix scaling custom axes, to use PC1 instead of 1

Thanks for the hint @antgonza
Merge pull request #32 from ElDeveloper/issue_5

Issue 5 -- Scaling method