Added a link to Glyph Lefkowitz's extending vs. embedding article, converted TODOs into rst comments.
Added a link to Glyph Lefkowitz's extending vs. embedding article, converted TODOs into rst comments.

berkus/enso,berkus/enso,berkus/enso,ebbypeter/enso,drdelta/notenso,ebbypeter/enso,drdelta/notenso,ebbypeter/enso,tectronics/enso,tectronics/enso,tectronics/enso,drdelta/notenso