Closer to V1

More fixes and features. Notable ones:

• 5f1f40e Fix zoom in FF
• 1555744 Fix canvas not going to the border of window
• 2629dc2 Store references associated with checkboxes
• 4346bdc Configure and store bom checkboxes
• 29a7d18 Get rid of most floats in pcbdata
• 9f41fa7 Add continuous redraw on drag setting
• 4be1f40 Pan and zoom
• d88f82e More sorting improvements
• 0796125 Add settings menu in html
• 8623142 Split html css and js into more files
• d72816e Improve sorting
• dc04dec Store view settings in localStorage
• fb3a623 Improve compatibility with KiCad 4