drm: implement syncobj and fence for VIRGL/VirtIO driver

Extract protocol-agnostic FenceTimeline from Intel to shared
src/drivers/fence.rs — atomic-based fence tracking suitable
for Intel, VIRGL, and AMD drivers.

Extract protocol-agnostic SyncobjManager from Intel to shared
src/drivers/syncobj.rs — syncobj create/destroy/signal/reset/
wait/query and sync_file fd export/import.

Wire both into VirtioDriver:
- Add FenceTimeline + SyncobjManager fields
- Implement all 5 GpuDriver syncobj trait methods
  (create, destroy, wait, export_fd, import_fd)
- Track fence seqnos in virgl_submit_3d (allocate
  before submit, signal after completion)

Intel fence.rs and syncobj.rs converted to thin re-export
modules pointing at shared sources — no behavioral change
for Intel driver.

This gives Mesa VIRGL userspace the standard DRM syncobj
API for GPU/compositor synchronization.

recipes/tools/file/source/python/setup.py

@@ -0,0 +1,27 @@
+# coding: utf-8
+
+from __future__ import unicode_literals
+
+from setuptools import setup
+
+with open('README.md', 'r') as fh:
+      long_description = fh.read()
+
+
+setup(name='file-magic',
+      version='0.4.0',
+      author='Reuben Thomas, Álvaro Justen',
+      author_email='rrt@sc3d.org, alvarojusten@gmail.com',
+      url='https://github.com/file/file',
+      license='BSD',
+      description='(official) libmagic Python bindings',
+      long_description=long_description,
+      long_description_content_type='text/markdown',
+      py_modules=['magic'],
+      test_suite='tests',
+      classifiers = [
+          'Intended Audience :: Developers',
+          'License :: OSI Approved :: BSD License',
+          'Natural Language :: English',
+          'Topic :: Software Development :: Libraries :: Python Modules',
+      ])