Add scaling by tab in the main GUI

This will contain one slider per each category in the mapping file.
Add updates to emperor.js and to the examples

This updated allows the scaling of the spheres on a per category basis,
a new callback has been added to respond to this behavior.

The callback from the slider takes a new value, it being the name of the
category.
Merge branch 'master' of git://github.com/qiime/emperor into issue_105
Merge pull request #111 from ElDeveloper/issue_105

Add a new tab for scaling per category
Merge branch 'issue_102' of git://github.com/antgonza/emperor into issue_102

Conflicts:
	emperor/support_files/emperor/js/emperor.js
	tests/scripts_test_data/make_emperor/biplot/emperor_required_resources/emperor/js/emperor.js
	tests/scripts_test_data/make_emperor/biplot_options/emperor_required_resources/emperor/js/emperor.js
	tests/scripts_test_data/make_emperor/emperor_colored_by/emperor_required_resources/emperor/js/emperor.js
	tests/scripts_test_data/make_emperor/emperor_output/emperor_required_resources/emperor/js/emperor.js
	tests/scripts_test_data/make_emperor/jackknifed_pcoa/emperor_required_resources/emperor/js/emperor.js
	tests/scripts_test_data/make_emperor/jackknifed_with_master/emperor_required_resources/emperor/js/emperor.js
	tests/scripts_test_data/make_emperor/pcoa_dob/emperor_required_resources/emperor/js/emperor.js
	tests/scripts_test_data/make_emperor/pcoa_dob_with_missing_custom_axes_values/emperor_required_resources/emperor/js/emperor.js
	tests/scripts_test_data/make_emperor/sorted_by_DOB/emperor_required_resources/emperor/js/emperor.js
	tests/scripts_test_data/make_emperor/vectors/emperor_required_resources/emperor/js/emperor.js
Fix bug with reset camera and camera settings

The camera was being reset as an initialization, but without reseting
the trackball controls; this cannot be done as the camera have to be set
before being able to reset it and to functionaly do this through the
program, you have to reset the trackball controls, else it won't go back
to the main position.
Add scaling for the main light in the scene
Change spaces to tabs in emperor.js
Update emperor.js in all examples