Here I start collecting information about required patches - work in progress.
Patch related new settings are:
TODO: since align_classes can be handled by the new Formatter engine, we could try to reduce patching the mutiple-classes handling (form_utils.js and alignment settings above).
advimage/image.htm and image.js
show IMG classes only, and link to open style library
table/table.htm and table.js
show TABLE classes only and link to style library
themes/advanced/editor_template_src.js
importClasses() to support "user_css" setting, so only Style Library font styles are shown
layer
add class, alignment, heading support by making an insert/edit dialog box for it. Removes absolute positioning support, thus DIVs can be aligned left or right float or center, and can be styled.
clearfloat
allows adding removing clear:both to block elements for easy formatting
appendafter
adds a paragraph after the current element (sometimes it's impossible to go between two elements or write after the last element) (two tables for example)