update MSWindows build docs
update MSWindows build docs

--HG--
extra : transplant_source : %CCZ%F0%A0%3AC3%F7I%F7AXE%AE%E1%05-%24%D0K
merge lxml-3.3 branch into master
simplify some code
simplify some code
add incremental XMPP serialisation example to docs
merge lxml-3.3 branch into master