Fix host version through out the builds.

Refactor HostVersion into its own class and use it everywhere host
artifacts are created. This includes the
- host nuget packages
- host installers (msi, pkg, deb)

scripts/dotnet-cli-build/Utils/Version.cs

@@ -0,0 +1,39 @@
+using System.Collections.Generic;
+
+namespace Microsoft.DotNet.Cli.Build
+{
+    public abstract class Version
+    {
+        public virtual int Major { get; set; }
+        public virtual int Minor { get; set; }
+        public virtual int Patch { get; set; }
+        public virtual int CommitCount { get; set; }
+        public virtual string CommitCountString => CommitCount.ToString("000000");
+        public virtual string ReleaseSuffix { get; set; }
+
+        public string GenerateMsiVersion()
+        {
+            // MSI versioning
+            // Encode the CLI version to fit into the MSI versioning scheme - https://msdn.microsoft.com/en-us/library/windows/desktop/aa370859(v=vs.85).aspx
+            // MSI versions are 3 part
+            //                           major.minor.build
+            // Size(bits) of each part     8     8    16
+            // So we have 32 bits to encode the CLI version
+            // Starting with most significant bit this how the CLI version is going to be encoded as MSI Version
+            // CLI major  -> 6 bits
+            // CLI minor  -> 6 bits
+            // CLI patch  -> 6 bits
+            // CLI commitcount -> 14 bits
+            var major = Major << 26;
+            var minor = Minor << 20;
+            var patch = Patch << 14;
+            var msiVersionNumber = major | minor | patch | CommitCount;
+
+            var msiMajor = (msiVersionNumber >> 24) & 0xFF;
+            var msiMinor = (msiVersionNumber >> 16) & 0xFF;
+            var msiBuild = msiVersionNumber & 0xFFFF;
+
+            return $"{msiMajor}.{msiMinor}.{msiBuild}";
+        }
+    }
+}