Increment commit of managed-download function.

An enormous amount of work as been done completing general tasks, and filling-out state management.
Finished last tasks prior to testing.

- The external download-agent now throws a particular exception when the
  download-worker prematurely stops the request.
- We now translate the entry mtime to the correct TZ when touching files.
- We now raise an exception when the download-request's mtime isn't TZ-aware.
- _SyncedResourceHandle is now aware of the physical downloaded file-path.
- Eliminated a couple of other to-dos.
- _SyncedResourceHandle now opens the physical file, forwards undefined
  method calls to the internal file-resource, and wraps those calls in fault-
  checks.
- Adjusted how we forward errors from the download-worker back to watchers.
- We now properly cleanup the _SyncedResourceHandle object, post-yield.

Now ready for testing.
Pylint-related fixes.
Formatting changes.
Download-agent debugging.

Switched to standard gevent from geventhttpclient for lack of available package.
Now ignore /.Python .
The download worker now uses a to make sure IPC is safe.

We'll have to refactor this to send this messages to main worker thread, and then funnel these back to foreground process.
Removed and ignored packaging directories.
Added path to tools.
Low-key bug-fixes and refactors.

- Refactored auth code for good-sense.
- auth_cache_filepath is no longer defaulted to a viable value (easier to debug).
- oauth singleton is no longer created at module-load. Was preempting our ability to set the creds file-path.
Disabled geventhttpclient. Not imp'd.
Added some debugging.
Merge branch 'dustin'