allow to have attributes with no value part in HTML head and body

--HG--
branch : 0.8
extra : source : 81dd5bc1f2d7532a6436013af712e3e4ccb88144
backported the other half of that change

--HG--
branch : 0.8
give listeners access to the container used to boot the addOns

--HG--
branch : 0.8
extra : source : 09da93b79028d0957f5021b598cda2a9146be303
prevent DoS attacks abusing the expensive password hashing by submitting extremely long passwords

--HG--
branch : 0.8
extra : source : aa6c4bd8654e206b1fb295dc88dd6ea289399295
remove non-addOn dependencies from the requirement list

We cannot be sure that we know all vendor libraries. For example, one addOn can
require "guzzle/http", whereas another one requires "guzzle/guzzle" (the
complete package). Composer will now install only the full package and hence
our addOn service would constantly think that "guzzle/http" is missing.
Without *deep* understanding of the package graph at runtime, we cannot resolve
this, so we start relying even more on Composer to put together a working
combination of packages.

If you clone your addOn manually, be sure you know what you're doing.

--HG--
branch : 0.8
extra : source : 139de76786bed6b86f1482179fe92df4a5ea0a2c
return a much more useful value from db->query()

--HG--
branch : 0.8
extra : source : 9ef60d15daad0a7d48eb70aa0a3147bcbaef7495
respect diabled flag

--HG--
branch : 0.8
extra : source : a43dd28df065c2623111497a7c1e2a380dd530a4
respect readonly too

--HG--
branch : 0.8
extra : source : bdea22dd6c1ff46ee948f9dfab82ccf7d83ed03e
version 0.8.3

--HG--
branch : 0.8
back to dev

--HG--
branch : 0.8
real 0.8.3

--HG--
branch : 0.8
back to dev

--HG--
branch : 0.8