Merge branch 'release-2.9.0' into develop

* release-2.9.0:
  Bump version to 2.9.0
Add dev prefix back to version in dev branch
Bumped the version in README.
Added back get_upload_id().
Merge pull request #1450 from reinhillmann/manifestchanges

Added back get_upload_id().
Fixing bogus docs regarding return value of import_key_pair.
Add eu-west-1 endpoint for Redshift.
Change calling_format override in storage_uri to be gs-specific.
Fixed missing raise introduced by 57a41897493e3b11fbbe47360a9d2f1033aae87d (fixes resumable download test failures)
Add clarifying comment about using OrdinaryCallingFormat in storage_uri.
Merge pull request #1455 from jterrace/calling-format-gs-specific

Change calling_format override in storage_uri to be gs-specific.
Trying to make the docs around the count param a bit more clear.
Fix typo bug in autoscale tutorial.
Allow port override in boto config
Merge pull request #1462 from thobrla/portoverride

Allow port override in boto config
Updated DynamoDB v2 to incorporate retries & checksums.
Fixed the error type checking.
Merge branch 'ddbv2-retries' into develop
Added a ``connect_redshift`` function for easier access to a ``RedShiftConnection``.
Change num_retries default for resumable download handler to be 6, to be consistent w/ num_retries elsewhere in the code