largefiles: introduce the 'composelargefilematcher()' method

This is a copy/paste (with the necessary tweaks) of the composenormalfilematcher
method currently on default, which does the inverse- this trims the normal files
out of the matcher.  It will be used in the next patch.

--HG--
branch : stable
largefiles: fix a spurious missing file warning with 'remove -A' (issue4053)

The bug report doesn't mention largefiles, but the given recipe doesn't fail
unless the largefiles extension is loaded.  The problem only affected normal
files, whether or not any largefiles are committed, and only files that have
not been committed yet.  (Files with an 'a' state are dropped from dirstate,
not marked removed.)  Further, if the named normal file never existed, the
warning would be printed out twice.

The problem is that the core implementation of remove() calls repo.status(),
which eventually triggers a dirstate.walk().  When the file isn't seen in the
filesystem during the walk, the exception handling finds the file in
dirstate, so it doesn't complain.  However, the largefiles implementation
called status() again with all of the original files (including the normal
ones, just dropped).  This time, the exception handler doesn't find the file
in dirstate and does complain.  This simply excludes the normal files from
the second repo.status() call, which the largefiles extension has no interest
is processing anyway.

--HG--
branch : stable
largefiles: fix a spurious missing file warning with forget (issue4053)

If an uncommitted and deleted file was forgotten, a warning would be emitted,
even though the operation was successful.  See the previous patch for
'remove -A' for the exact circumstances, and details about the cause.

--HG--
branch : stable
demandimport: blacklist distutils.msvc9compiler (issue4475)

This module depends on _winreg, which is windows-only. Recent versions
of setuptools load distutils.msvc9compiler and expect it to
ImportError immediately when on non-Windows platforms, so we need to
let them do that. This breaks in an especially mystifying way, because
setuptools uses vars() on the imported module. We then throw an
exception, which vars doesn't pick up on well. For example:

In [3]: class wat(object):
   ...:     @property
   ...:     def __dict__(self):
   ...:         assert False
   ...:

In [4]: vars(wat())
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-4-2781ada5ffe6> in <module>()
----> 1 vars(wat())

TypeError: vars() argument must have __dict__ attribute

Which is similar to the problem we run into.

--HG--
branch : stable