Major Changes. Now packed into a class + config file (config.php).

New feature - support for post meta values. Following shortcuts are supported:

{date} - will be replaced with post publishing date
{title} - will be replaced with post title
{postmeta_YOURMETAKEY} - will be replaced with the content of the post meta field with the name/key YOURMETAKEY. Multiple keys are supported too - eg:

 'content' => '{date} - {postmeta_testadd} {postmeta_test2} click here for more informations!'

is a valid expression - it will be converted to

'POST DATE - testadd-CUSTOM FIELD VALUE test2-CUSTOM FIELD VALUE