* Add an (opt-in) crossprobe interface
 * Add extensible sexp parser
 * Clean up html/javascript a bit
 * Implement a theme system
 * Implement kicad_pro, kicad_sch, kicad_sym, kicad_wks handlers
 * Index and include all symbol properties in the mouseover box
 * Make the feedback URL based on a project property
 * Pull in js library dependencies with proper attribution
 * Pull out embedded SVGs for easier maintenance and attribution
 * Replace pypng with a simple png encoder
 * Support forward/backward mouse buttons
 * Use REUSE for license tracking
 * Reorganize directory structure