Suppress External Rules (#585)
Suppress External Rules (#585)

* External/Custom rule supression

* Revert to the previous GetExternalRecord() call on all external rules, rather than 1-by-1 to continue to take advantage of the runspacepool stuff.
New SupressRule() function that takes a single DiagnosticRecord and list of suppressions - bounces the RuleName of the record against that list.

daviwil/PSScriptAnalyzer,PowerShell/PSScriptAnalyzer,juneb/PSScriptAnalyzer,dlwyatt/PSScriptAnalyzer