misc. minor fixes for artresizer (#64)
misc. minor fixes for artresizer (#64)

- Safer proxy resize. The URL parameters are now properly encoded. And a
  spurious additional request has been removed.
- Removed manual search of $PATH. Invoking "convert" without a path does this
  automatically.
- More pyflakes-friendly test import of PIL.
- Do not delete the NamedTemporaryFile -- doing so creates a race condition
  where the file might be created between the filename generation and the tool
  invocation.

google-code-export/beets,google-code-export/beets,google-code-export/beets