start reorganizing docs, write more docs, shift plugin docs, to proper documentation,

use sphinx, remove old docs ... work in progress.

--HG--
branch : trunk

doc/conftest.py

@@ -1,8 +0,0 @@
-#XXX make work: excludedirs = ['_build']
-import py
-pytest_plugins = ['pytest_restdoc']
-collect_ignore = ['test/attic.txt']
-
-def pytest_runtest_setup(item):
-    if item.fspath.ext == ".txt":
-        py.test.importorskip("pygments") # for raising an error