Move MAML spec to version 0.12.0-prerelease.
Revert "Move MAML spec to version 0.12.0-prerelease."

This reverts commit d61abd6cf637bf35ed8e008e83a5d6ef63afeefe.
Publish Nuget spec to version 0.12.0-prerelease
change version in package config to the right one.
Merge pull request #855 from akhadem/master

ADF MAML 0.12.0-preview with latest specs change