Add AclBuilder to all ProcessDirectory invocations

[elordahl]

Receiving the following exception due to missing $AclBuilder parameter. Was this omission intentional? An alternative would be a null check prior to use of the var.

Generate_IIS : You cannot call a method on a null-valued expression.
At C:\Program Files\WindowsPowerShell\Modules\Image2Docker\1.8.2\Functions\Private\GenerateDockerfile.ps1:34 char:23
+ ... ockerfile = & "Generate_$Artifact" -MountPath $MountPath -ManifestPat ...
+                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [Generate_IIS], RuntimeException
    + FullyQualifiedErrorId : InvokeMethodOnNull,Generate_IIS

DEBUG:   60+      >>>> $null = $AclBuilder.AppendLine('RUN $path=' + "'C:$targetPath'; ``")

@sixeyed

[pdevine]

Seems reasonable.

[pdevine]

@sixeyed Can you give it a final review?