message: Recognize Drupal placeholders
  Add syntax highlighting for Drupal variable placeholders.
  They take the form of %var or :var, the variable name is not
  terminated and is recognized just by being followed by a character that
  isn't allowed in variable name (which is [\w-]).
diff: @@ -212,9 +212,11 @@ std::wregex RE_RUBY_FORMAT(LR"(%(\d+\$)?[-+ #0]{0,5}(\d+|\*)?(\.(\d+|\*))?(hh|ll
  // variables expansion for various template languages
  std::wregex RE_COMMON_PLACEHOLDERS(
  //
  - // | |
  - LR"(%[\w.-]+%|%?\{[\w.-]+\}|\{\{[\w.-]+\}\})",
  - // | | | | |
  + // | | |
  + LR"(%[\w.-]+%|%?\{[\w.-]+\}|\{\{[\w.-]+\}\}|[@%:][\w-]+)",
  + // | | | | | | |
  + // | | | +--------- Drupal: non-terminated @var, %var or :var
  + // | | | !MUST be last in regex because of lack of termination character!
  // | | |
  // | | +----------------------- {{var}}
  // | |
  