uniquify the wom-specific reference classes to avoid conflicts with injected html content
a bit more paranoia on sieve element classes unicity
uniquify title list related elements
cleanup sieve html classes, uniquify and reduce some class names
uniquify warning messages and progress bar
mark as read only when going to a newer item and show progress relative to loaded content only
use 'h' to siwtch the headlines display
small improvement to reload messag's hint for keybinding