Bug fix: default pitchWheel deviation now set correctly

When setting the default pitchWheel deviation, the
pitch wheel is now also set to its centre position
(otherwise its effective position can be wrong).
Beautified: score options are now set just once.

A score's default options are now set once
(in Controls.js setScore() ), at the same time as the
SVG pages are loaded. This allowed some functions
to be moved inside others, thus reducing the scope
in which they are available.
Added a temporary track.maxVolumes option to
Study2c3.1 to test that this works in non-assisted
performances (it does).
Minimum pressure control defaults changed.

This performer's pressure control and minimum
pressure options (only used in assisted performances)
now default to volume, value 64. The old defaults
(aftertouch, value 127) weren't so good.
Reset Study2c3.1 track.maxVolumes to 100 100 100

Did this is assistantPerformer.html.
Set track.maxVolumes of Study 3 sketch 1 to 100 too.