patch configure to correctly find libxml2
Redmine #4716: Lots of fixes to dirname(), esp. on Windows.

These problems were fixed:
* AddSlash() always adds Unix slash when argument is empty.
* DeleteSlash() removes root slash.
* DeleteSlash() does not handle repeated path separators.
* FirstFileSeparator() returns NULL on all relative Unix paths, even
  if it has a file separator.
* ChopLastNode() gives empty string when removing last directory
  component of a relative path. It should give '.'.
* ChopLastNode() does not handle Windows drive letters.
* ChopLastNode() does not handle repeated path separators.
* IsAbsoluteFileName() does not handle absolute paths on Windows that
  don't start with a drive letter. Both types are considered absolute
  paths.

This also fixes a Windows issue where creating a directory in policy
would lead to an error message about not being able to chdir into a
directory with the name ''. This was due to the final root slash not
being preserved.
Merge pull request #1877 from kacfengine/dirname_fixes

Redmine #4716: Lots of fixes to dirname(), esp. on Windows.
Merge pull request #1878 from MatthewCattell/mingw-libxml2-configure-fix

patch configure to correctly find libxml2
Switching to masterfiles inventory_os.description for attribute_name OS for portability
Revert "Remove uninitialized buffers as source of entropy."

This reverts commit 570724e752cf131132bb88e65a031f700b0ac424.

The reason is that in a chroot testing environment, there isn't enough
entropy available to satisfy OpenSSL, so it will bail out. Reverting
is not the correct fix for the problem, but right now we need tests to
pass, so postponing this for later.

Conflicts:

	libpromises/crypto.c