v0.5.0 Release

Bigtable (v0.5.x)

• Restore support for gcc-4.8.
• @remyabel cleaned up some hard-coded zone names in the examples.
• More experimental asynchronous APIs, including AsyncReadRows. Note that we
  expect to change all these experimental APIs as described in
  #1543.
• @remyabel contributed changes to disable the unit and integration tests. This
  can be useful for package maintainers.
• New Bigtable filter wrapper that accepts a single column.
• Breaking Change: remove the as_proto_move() member functions in favor
  of as_proto() &&. With the latter newer compilers will warn if the object
  is used after the destructive operation.

Common

• Support compiling with gcc-4.8.
• Fix GCP_LOG() macro so it works on platforms that define a DEBUG
  pre-processor symbol.
• Use different PRNG sequences for each backoff instance, previously all the
  clones of a backoff policy shared the same sequence.
• Workaround build problems with Xcode 7.3.

Storage (v0.3.x)

• Try to use the exception mask in the IOStream classes
  (storage::ObjectReadStream and storage::ObjectWriteStream). This allows
  applications to check errors locally via rdstate(). Note that applications
  that disable exceptions altogether must check the status() member function
  for these IOStream classes. It is impossible to set the rdstate() for all
  failures when exceptions are disabled.
• Support reading only a portion of a Blob.
• Support building with gcc-4.8.
• Many internal changes to better support applications that disable exceptions.
  A future release will include APIs that do not raise exceptions for error
  conditions.
• @remyabel contributed changes to disable the unit and integration tests. This
  can be useful for package maintainers.
• Implement a function to create signed URLs (Client::CreateV2SignedUrl).
• Support resumable uploads in any upload operation.