Bump up ADF MAML nugets so that no internal types are leaking.
Clean the app.config from ADF csproj.
Update ChangeLog.txt
Merge pull request #644 from yitao-zhang/release-0.8.10

Bump up ADF MAML nugets so that no internal types are leaking.
Merge branch 'release-0.8.10' of https://github.com/Azure/azure-sdk-tools-pr into release-0.8.10