Update NuGet.exe to v2.8.0
Remove .nuget directory from the solution
Update project to use NuGet Automatic Restore
Remove obsolete CombinePackageConfigs task
Merge pull request #576 from jrusbatch/package-restore

Update solution to use NuGet v2.8's Automatic Restore
parser should print an error message correctly
if parser fails, handler should look up scriptcs.opts
if that is not present just use default args since we failed anyway
added tests, removed an obsolete test
Merge pull request #578 from filipw/577

fix for 577