emacs-darkroom 0.2 Remove visual distractions and focus on writing

darkroom-mode makes visual distractions disappear. The mode-line is temporarily elided, text is enlarged and margins are adjusted so that it's centered on the window.

darkroom-tentative-mode is similar, but it doesn't immediately turn-on darkroom-mode, unless the current buffer lives in the sole window of the Emacs frame (i.e. all other windows are deleted). Whenever the frame is split to display more windows and more buffers, the buffer exits darkroom-mode. Whenever they are deleted, the buffer re-enters darkroom-mode.