Log Message:
Updated to p5-Petal to 2.18.

2.18 Tue Jan 17 13:01:00 2006
    - $Petal::CodeGenerator::PI_RE should be applied newline insensitively
    - pod fixes
    - Cookbook tal:repeat example (DSL)
    - pod note that on-error isn't fully implemented
    - defang html metacharacters in on-error output
    - undo 2.16 $Petal::Hash::String::VARIABLE_RE_BRACKETS ${1} regression