new notifications spec and implementation

allows autoClosing
proxiedSites modal copy fix

comment out "content on other sites included on these sites will also be proxied automatically"
pending getlantern/lantern#465
add "important" alert type, alias of "error" for now
delintification
ditch restart option in sanity modal, make reset button of settingsLoadFailure match sanity's
animate arcs connecting you to peers
copy tweak