preparation for multiscreen
parsing screens information
fixing layout of "orblank" step
first multiscreen configuration
backup commit

some (not all) multiscreen support implemented, not tested
better demo of multiscreen
finalizing multiscreen support

but `verify()` still needs more work
presentation tweaks, adding comments
Merge branch 'multiscreen'
validation fix

URIs apparently cannot have the vertical bar in them, according to the
W3C validator
fixing comment
mostly comment fixes