Merge master into future

[ghost]

This is an automatically generated pull request from master into future.

@dotnet/roslyn-infrastructure:

git remote add vslsnap-roslyn "https://github.com/vslsnap/roslyn.git"
git fetch vslsnap-roslyn
git fetch upstream
git checkout merge-master-into-future20160527-150023
git reset --hard upstream/future
git merge upstream/master
# Fix merge conflicts
git commit
git push vslsnap-roslyn merge-master-into-future20160527-150023 --force

Once the merge can be made and all the tests pass, you are free to merge the pull request.

[ghost]

@dotnet-bot test vsi please

[panopticoncentral]

@dotnet-bot retest windows_debug_unit32_prtest please
// Previous failure: http://dotnet-ci.cloudapp.net/job/dotnet_roslyn/job/future/job/windows_debug_unit32_prtest/98/
// Retest reason:

[panopticoncentral]

@dotnet-bot retest windows_vsi_p2_open_prtest please
// Previous failure: http://dotnet-ci.cloudapp.net/job/Private/job/dotnet_roslyn-internal/job/future/job/windows_vsi_p2_open_prtest/14/
// Retest reason: