implemented --timeout=n option and fixed a bug

* updated the TODO to remove the --timeout option todo.
* the commands load, search and update are the only commands i want to have
--timeout. this said, the [--rm-drive --sync-drive] options in update are not
supported for --timeout.
* updated ftrack.py __doc__ str to include --timeout.
* all util/apis/ now take in a timeout param. the default is set to 10 seconds.
* this also means the ENV['TIMEOUT'] is no longer used and removed.

* there was a bug in the util/identifer.py module regarding pathing. a relative
path was passed into the load method and it assumed it was absolute. to fix
this, the `path` param is now removed, default cached id paths are used and to
be safe, the cwd is changed to dirname(__file__).