Unify ignore/replacement lists for the two contrib ps1 scripts.

Tools/dump_contributors_since.ps1

@@ -8,16 +8,8 @@ param(
 
     [Nullable[DateTime]]$until);
 
-$replacements = @{
-    "moonheart08" = "moony"
-    "Elijahrane" = "Rane"
-    "ZeroDayDaemon" = "Daemon"
-    "ElectroJr" = "ElectroSR"
-}
-
-$ignore = @{
-    "PJBot" = $true
-}
+$scriptDir = Split-Path -Path $MyInvocation.MyCommand.Definition -Parent
+. $(join-path $scriptDir contribs_shared.ps1)
 
 $engine = & "$PSScriptRoot\dump_commits_since.ps1" -repo space-wizards/RobustToolbox -since $since -until $until
 $content = & "$PSScriptRoot\dump_commits_since.ps1" -repo space-wizards/space-station-14 -since $since -until $until