phetsims/scenery-phet#52 change alignment 'bottom' to 'centerBottom' to be consistent with scenery layout values
phetsims/scenery-phet#52 change 'score' to 'points' throughout the interface and internal implementation, with the exception of the type name (that will be changed last)
phetsims/scenery-phet#52 change default option values to match the majority of use cases, instead of Balancing Act's requirements
phetsims/scenery-phet#52 fix more default options, replace option.pointsTextSize with option.pointsFont