made sitelib clean up after itself; note to self: investigate using pipes

sitelib.lua

@@ -33,6 +33,7 @@ function sitelib.parsepage(s)
  f:write(page.md)
  f:close()
  page.html = io.popen("markdown "..fn):read("*a")
+ os.execute("rm "..fn)
  -- SKS specific stuff starts here
  page.html=page.html:gsub("++leftcol",'<div class="left-column">')
  page.html=page.html:gsub("++colbreak",'</div><div class="left-column">')