Added basic generic tool collection

lib/core/tools.psm1

@@ -0,0 +1 @@
+Import-IcingaDirectoryModules -LibDirectory (Join-Path -Path $PSScriptRoot -ChildPath $MyInvocation.MyCommand.Name) -ForceReload;

lib/core/tools/New-StringTree.psm1

@@ -0,0 +1,19 @@
+function New-StringTree()
+{
+    param(
+        [int]$Spacing
+    )
+    
+    if ($Spacing -eq 0) {
+        return '';
+    }
+
+    [string]$spaces = ' \_ ';
+    
+    while ($Spacing -gt 1) {
+        $Spacing -= 1;
+        $spaces = '   ' + $spaces;
+    }
+
+    return $spaces;
+}

lib/core/tools/Test-Numeric.psm1

@@ -0,0 +1,3 @@
+function Test-Numeric ($number) {
+    return $number -Match "^[\d\.]+$";
+}