[mono] Set AssemblyName.CultureInfo instead of AssemblyName.CultureName
[mono] Set AssemblyName.CultureInfo instead of AssemblyName.CultureName

Mono throws NotImplementedException for AssemblyName.set_CultureName, so
use AssemblyName.CultureInfo instead.

Not setting the culture at all, resulted in the fullname lacking the
Culture, `System, Version=2.0.5.0, PublicKeyToken=7cec85d7bea7798e,
Retargetable=Yes`, which caused:

Microsoft.Common.CurrentVersion.targets(1980,5): error MSB4018: System.IO.FileLoadException: The assembly name is invalid. [/Users/ankit/dev/md-addins/MonoDevelop.MonoDroid/MonoDevelop.MonoDroid/MonoDevelop.MonoDroid.csproj]
Microsoft.Common.CurrentVersion.targets(1980,5): error MSB4018:   at System.Reflection.AssemblyName..ctor (System.String assemblyName) [0x0004c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/corlib/System.Reflection/AssemblyName.cs:102  [/Users/ankit/dev/md-addins/MonoDevelop.MonoDroid/MonoDevelop.MonoDroid/MonoDevelop.MonoDroid.csproj]
Microsoft.Common.CurrentVersion.targets(1980,5): error MSB4018:   at Microsoft.Build.Tasks.NativeMethods.CompareAssemblyIdentity (System.String assemblyIdentity1, System.Boolean fUnified1, System.String assemblyIdentity2, System.Boolean fUnified2, System.Boolean& pfEquivalent, Microsoft.Build.Tasks.NativeMethods+AssemblyComparisonResult& pResult) [0x00021] in /Users/ankit/dev/msbuild/src/XMakeTasks/NativeMethods.cs:1135  [/Users/ankit/dev/md-addins/MonoDevelop.MonoDroid/MonoDevelop.MonoDroid/MonoDevelop.MonoDroid.csproj]
Microsoft.Common.CurrentVersion.targets(1980,5): error MSB4018:   at Microsoft.Build.Tasks.ReferenceTable.ResolveAssemblyNameConflict (Microsoft.Build.Tasks.AssemblyNameReference assemblyReference0, Microsoft.Build.Tasks.AssemblyNameReference assemblyReference1) [0x000db] in /Users/ankit/dev/msbuild/src/XMakeTasks/AssemblyDependency/ReferenceTable.cs:2242  [/Users/ankit/dev/md-addins/MonoDevelop.MonoDroid/MonoDevelop.MonoDroid/MonoDevelop.MonoDroid.csproj]
Microsoft.Common.CurrentVersion.targets(1980,5): error MSB4018:   at Microsoft.Build.Tasks.ReferenceTable.ResolveConflictsBetweenReferences () [0x00044] in /Users/ankit/dev/msbuild/src/XMakeTasks/AssemblyDependency/ReferenceTable.cs:1818  [/Users/ankit/dev/md-addins/MonoDevelop.MonoDroid/MonoDevelop.MonoDroid/MonoDevelop.MonoDroid.csproj]
Microsoft.Common.CurrentVersion.targets(1980,5): error MSB4018:   at Microsoft.Build.Tasks.ReferenceTable.ResolveConflicts (Microsoft.Build.Tasks.DependentAssembly[]& idealRemappings, Microsoft.Build.Tasks.AssemblyNameReference[]& conflictingReferences) [0x00007] in /Users/ankit/dev/msbuild/src/XMakeTasks/AssemblyDependency/ReferenceTable.cs:1846  [/Users/ankit/dev/md-addins/MonoDevelop.MonoDroid/MonoDevelop.MonoDroid/MonoDevelop.MonoDroid.csproj]
Microsoft.Common.CurrentVersion.targets(1980,5): error MSB4018:   at Microsoft.Build.Tasks.ResolveAssemblyReference.Execute (Microsoft.Build.Shared.FileExists fileExists, Microsoft.Build.Shared.DirectoryExists directoryExists, Microsoft.Build.Tasks.GetDirectories getDirectories, Microsoft.Build.Tasks.GetAssemblyName getAssemblyName, Microsoft.Build.Tasks.GetAssemblyMetadata getAssemblyMetadata, Microsoft.Build.Shared.GetRegistrySubKeyNames getRegistrySubKeyNames, Microsoft.Build.Shared.GetRegistrySubKeyDefaultValue getRegistrySubKeyDefaultValue, Microsoft.Build.Tasks.GetLastWriteTime getLastWriteTime, Microsoft.Build.Tasks.GetAssemblyRuntimeVersion getRuntimeVersion, Microsoft.Build.Shared.OpenBaseKey openBaseKey, Microsoft.Build.Tasks.GetAssemblyPathInGac getAssemblyPathInGac, Microsoft.Build.Tasks.IsWinMDFile isWinMDFile, Microsoft.Build.Tasks.ReadMachineTypeFromPEHeader readMachineTypeFromPEHeader) [0x0069e] in /Users/ankit/dev/msbuild/src/XMakeTasks/AssemblyDependency/ResolveAssemblyReference.cs:2207  [/Users/ankit/dev/md-addins/MonoDevelop.MonoDroid/MonoDevelop.MonoDroid/MonoDevelop.MonoDroid.csproj]
Microsoft.Common.CurrentVersion.targets(1980,5): error MSB4018:   at Microsoft.Build.Tasks.ResolveAssemblyReference.Execute () [0x00001] in /Users/ankit/dev/msbuild/src/XMakeTasks/AssemblyDependency/ResolveAssemblyReference.cs:2903  [/Users/ankit/dev/md-addins/MonoDevelop.MonoDroid/MonoDevelop.MonoDroid/MonoDevelop.MonoDroid.csproj]
Microsoft.Common.CurrentVersion.targets(1980,5): error MSB4018:   at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute () [0x0002a] in /Users/ankit/dev/msbuild/src/XMakeBuildEngine/BackEnd/TaskExecutionHost/TaskExecutionHost.cs:632  [/Users/ankit/dev/md-addins/MonoDevelop.MonoDroid/MonoDevelop.MonoDroid/MonoDevelop.MonoDroid.csproj]
Microsoft.Common.CurrentVersion.targets(1980,5): error MSB4018:   at Microsoft.Build.BackEnd.TaskBuilder+<ExecuteInstantiatedTask>d__26.MoveNext () [0x002bf] in /Users/ankit/dev/msbuild/src/XMakeBuildEngine/BackEnd/Components/RequestBuilder/TaskBuilder.cs:787  [/Users/ankit/dev/md-addins/MonoDevelop.MonoDroid/MonoDevelop.MonoDroid/MonoDevelop.MonoDroid.csproj]

.. because a `Retargetable` requires a fully qualified assembly name.

bug: https://bugzilla.xamarin.com/show_bug.cgi?id=53149

mono/msbuild,mono/msbuild,mono/msbuild,mono/msbuild