add swipe and pager components for webcams

swiper integrates swipe and pager so that when user swipes the webcam
pager updates itself, and whenever the user clicks the pager webcam
display is updated

switch to pixel padding on .panel - we used .8em before which scales
better but it makes the content width fractional (when expressed in
pixels) which confuses the swipe component

for now empty and filled circle are created with unicode but that might
not work everywhere - we need to use our own cusom font here