docs: update README, CONTRIBUTING and LICENSE, remove CONTRIB
Add Bucket.copy_key impl from PR #99, with tests.

Hand apply / fix up patch from gsalgado's un-mergeable commit:
https://github.com/gsalgado/gcloud-python/commit/1c80d618f265c01ac01a794b5af12f03a6438fb1.
Add Key.rename from PR #99, with test.

Manually applies patch from gsalgado:
https://github.com/gsalgado/gcloud-python/commit/1c80d618f265c01ac01a794b5af12f03a6438fb1

But changes semantics to return the new key instance, leaving the original
key unchanged.
100% branch coverage for gcloud.datastore.helpers.

Surfaced bug w/ unknown type passed to get_protobuf_attribute_and_value().
Toward 100% branch coverage for gcloud.datastore.key.

Surfaced bug w/ path element holding both id and name in Key.from_protobuf.
Toward 100% branch coverage for gcloud.datastore.key.

Cover edge condition in Key.to_protobuf where dataset has empty ID.
Toward 100% branch coverage for gcloud.datastore.key.

Cover edge conditions in Key.to_protobuf where path elements are missing keys.
100% branch coverage for gcloud.datastore.key.

Cover edge conditions in Key.{kind,id,name} where path is empty.
100% branch coverage for gcloud.datastore.query.

Edge cases in Query.ancestor w/ existing non-ancestor filters.
100% branch coverage for gcloud.datastore.test_key.

Don't worry about path elem w/o kind.
100% branch coverage for gcloud.storage.acl.

Edge case in ACL.__iter__ for empty role.
100% branch coverage for gcloud.storage.connection.

Exercise Connection.delete_bucket w/ 'force' passed as False.
Don't derive from object w/o need.

Incorporate feedback from @dhermes.
Appease pylint E261.
Ensure that Key.rename actually deletes old key as documents.

Incorporate feedback from @dhermes.
Merge pull request #224 from tseaver/pr_99-gsalgado-master

Rebase PR #99 and fix up
Suppress unit test coverage checks in demo code.

Having coveralls complain about uncovered functest / demo code is not helpful.
Silence Python 2.6 deprecation of exception.message.
Merge pull request #227 from tseaver/silence_py26_deprecation_for_exception_message

Silence Python 2.6 deprecation of exception.message.
Merge pull request #226 from tseaver/coverage-ignore_demo_modules

Suppress unit test coverage checks in demo code.