Argument validation for debugging on staging.
Fix the null reference exception coming from AutomaticPackageCurator when curatedFeed has been loaded without including Packages.
Fix #675 - Packages with .CS in the name are unreachable.
Fix still another missing includePackages: true causing null references during package curation (this time in TagBasedPackageCurator) and make all of the includePackages parameters non-optional since NOT thinking hard enough about whether they get included seems to be a common cause of bugs.
Remove .AsQueryable() calls which are non-optimal and use typed variables instead.
Fixing style feedback from code review.
Remove controversial Argument class. We can use code contracts for this later, will work on this in preview branch.