hgext3rd: move 'simple4server' as 'evolve.serveronly'
We also more the server only extension into hgext3rd. We makes it a python
sub-module of evolve for two reasons:
* less polution in the hgext3rd namespace,
* this make it possible to share the code between 'evolve' and
'evolve.serveronly' instead of duplicating it.
note that we now install the extension too
doc generated with sphinx. tutorial exported using sphinxedhg
http://hg.piranha.org.ua/sphinxedhg/