~/.Xresources: Enable urgency bell and remove the fullscreen hack.

.Xresources

!! urxvt settings
URxvt*scrollBar:            false
URxvt*urgentOnBell:         true
URxvt*font:                 xft:Monaco for Powerline:regular:size=11
URxvt*imFont:               xft:Monaco for Powerline:regular:size=11
URxvt*italicFont:           xft:Monaco for Powerline:italic:size=11
URxvt*boldItalicFont:       xft:Monaco for Powerline:bold:italic:size=11
URxvt.perl-ext-common:      default,fullscreen,url-select
URxvt.perl-ext-common:      default,url-select
URxvt.keysym.M-u:           perl:url-select:select_next
URxvt.urlLauncher:          chromium
URxvt.underlineURLs:        true
URxvt.keysym.F11:           perl:fullscreen:switch