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
Merge branch 'master' of git://github.com/qiime/emperor into light_fixes
Change position of the light when scaling

Not changing the position of the light when scaling caused the elements
in the scene to have "funny-looking" shadow; this was caused because the
light object wasn't changing it's current position.
Merge pull request #37 from ElDeveloper/light_fixes

Light fixes -- Lighting of the scene looks more natural
Add all_tests.py script

This script is ported from github.com/qiime/evident with some minor
modifications.

This should fix #36
Merge pull request #38 from ElDeveloper/issue_36

Add all_tests.py script
Merge branch 'master' of git://github.com/qiime/emperor into issue_11