windows build fixes: all tests should pass, ci with appveyor
- add appveyor.yml
- path fixes for windows, use os.path.join
- templates_dir: use '/' always for jinja2 paths
- auto colls: ensure chdir before deleting dir
- recorder: ensure warc writer is always closed
- recorder: disable locking in warcwriter on windows for now (read access not avail, shared
lock seems to not be working)
- zipnum: ensure block is closed after read!
- cached dir test: wait before adding file
- tests: adjust timeout tests to allow more leeway in timing
