[svn r57754] * introduce py.test.collect.File (File for py or non-py files)

* introduce py.test.collect.Collector.collect_by_name and
  special case it for Directories to allow specifying
  files that would otherwise be ignored because of filters.
* fix py/doc/conftest to work with new API
* refactor py/doc/test_conftest.py to use suptest helper
* avoid old APIs in some more places.

--HG--
branch : trunk

py/compat/conftest.py

@@ -1,5 +1,5 @@
 import py
 
 class Directory(py.test.collect.Directory):
-    def listdir(self):
-        py.test.skip("compat tests currently need to be run manually")
+    def collect(self):
+        py.test.skip("compat tests need to be run manually")