#137 added guard clauses
installed LiteGuard.Source package into ScriptCs.Core only and linked from other projects
created ScriptCs.ruleset based on MS recommended rules and added CA1062: Validate arguments of public methods
Merge pull request #242 from adamralph/137-guard-clauses

#137 added guard clauses
Bump the version to v0.5.0-alpha
Merge remote-tracking branch 'upstream/dev' into dev

* upstream/dev:
  Bump the version to v0.5.0-alpha
  #137 added guard clauses installed LiteGuard.Source package into ScriptCs.Core only and linked from other projects created ScriptCs.ruleset based on MS recommended rules and added CA1062: Validate arguments of public methods