Delete image files that don't have any name references in source files

clean-unreferenced-files.ps1

function FindAny() {
  param($name)
  $found = Get-ChildItem . -Recurse -Include *.js, *.css, *.html, *.xml |
  ? { $_.FullName -notmatch "node_modules" -and $_.FullName -notmatch "bower_components" } |
  Select-String $name
  return ($found | Measure-Object -Line).Lines -gt 0;
}

Get-ChildItem "web\images" | ? { -Not (FindAny $_.Name) } | rm