Change Action Conflict log message.
Split 'params' in make_request to 'subresource'+'params'

Previously these were kind of ambiguous and make_request would
decipher between url params vs subresource by checking if `params`
was a dict or a string. Now it is more explicit. Also added
basic support for security tokens for use with temporary security
credentials.
Change to path-style requests

Virtual hosted style requests (ie: <bucketname>.s3.aws.com) don't
work with anything but all lowercase bucket names, so I switched
to path style instead.
Add string to sign to verbose output.

Useful as s3 response errors that complain about bad signatures
always provide the proper string to sign. This makes it easier
to figure out what s3tup has done wrong.
Make non-verbose output prettier
Add security token to cli.
Add support for requester pays.