Bug 1253359 - Vendor in Pytest 2.9.2 and Py 1.4.31 r=gps

Vendor in Pytest (2.9.2) and its requirement Py (1.4.31),
so that it can be used for e.g. the Marionette
harness unit tests and a pytest plugin for mozlog.

Copy pytest and py package directories (extracted from
tars on Pip) into `mozilla-central/python/`, removing
some support files (e.g. changelog, docs, tests).
Add both `.pth` entries to `virtualenv_packages.txt`.
Add both paths to `SEARCH_PATHS` in `mach_bootstrap.py`.

MozReview-Commit-ID: IOTCOUxX8R9

python/pytest/_pytest/_argcomplete.py

@@ -0,0 +1,101 @@
+
+"""allow bash-completion for argparse with argcomplete if installed
+needs argcomplete>=0.5.6 for python 3.2/3.3 (older versions fail
+to find the magic string, so _ARGCOMPLETE env. var is never set, and
+this does not need special code.
+
+argcomplete does not support python 2.5 (although the changes for that
+are minor).
+
+Function try_argcomplete(parser) should be called directly before
+the call to ArgumentParser.parse_args().
+
+The filescompleter is what you normally would use on the positional
+arguments specification, in order to get "dirname/" after "dirn<TAB>"
+instead of the default "dirname ":
+
+   optparser.add_argument(Config._file_or_dir, nargs='*'
+                               ).completer=filescompleter
+
+Other, application specific, completers should go in the file
+doing the add_argument calls as they need to be specified as .completer
+attributes as well. (If argcomplete is not installed, the function the
+attribute points to will not be used).
+
+SPEEDUP
+=======
+The generic argcomplete script for bash-completion
+(/etc/bash_completion.d/python-argcomplete.sh )
+uses a python program to determine startup script generated by pip.
+You can speed up completion somewhat by changing this script to include
+  # PYTHON_ARGCOMPLETE_OK
+so the the python-argcomplete-check-easy-install-script does not
+need to be called to find the entry point of the code and see if that is
+marked  with PYTHON_ARGCOMPLETE_OK
+
+INSTALL/DEBUGGING
+=================
+To include this support in another application that has setup.py generated
+scripts:
+- add the line:
+    # PYTHON_ARGCOMPLETE_OK
+  near the top of the main python entry point
+- include in the file calling parse_args():
+    from _argcomplete import try_argcomplete, filescompleter
+   , call try_argcomplete just before parse_args(), and optionally add
+   filescompleter to the positional arguments' add_argument()
+If things do not work right away:
+- switch on argcomplete debugging with (also helpful when doing custom
+  completers):
+    export _ARC_DEBUG=1
+- run:
+    python-argcomplete-check-easy-install-script $(which appname)
+    echo $?
+  will echo 0 if the magic line has been found, 1 if not
+- sometimes it helps to find early on errors using:
+    _ARGCOMPLETE=1 _ARC_DEBUG=1 appname
+  which should throw a KeyError: 'COMPLINE' (which is properly set by the
+  global argcomplete script).
+"""
+
+import sys
+import os
+from glob import glob
+
+class FastFilesCompleter:
+    'Fast file completer class'
+    def __init__(self, directories=True):
+        self.directories = directories
+
+    def __call__(self, prefix, **kwargs):
+        """only called on non option completions"""
+        if os.path.sep in prefix[1:]: #
+            prefix_dir = len(os.path.dirname(prefix) + os.path.sep)
+        else:
+            prefix_dir = 0
+        completion = []
+        globbed = []
+        if '*' not in prefix and '?' not in prefix:
+            if prefix[-1] == os.path.sep:  # we are on unix, otherwise no bash
+                globbed.extend(glob(prefix + '.*'))
+            prefix += '*'
+        globbed.extend(glob(prefix))
+        for x in sorted(globbed):
+            if os.path.isdir(x):
+                x += '/'
+            # append stripping the prefix (like bash, not like compgen)
+            completion.append(x[prefix_dir:])
+        return completion
+
+if os.environ.get('_ARGCOMPLETE'):
+    try:
+        import argcomplete.completers
+    except ImportError:
+        sys.exit(-1)
+    filescompleter = FastFilesCompleter()
+
+    def try_argcomplete(parser):
+        argcomplete.autocomplete(parser)
+else:
+    def try_argcomplete(parser): pass
+    filescompleter = None