Add a 'logDocuments' configuration option
   * false by default
   * if true, logs files being processed with "lifecycle" logging level
   * closes #21
Merge pull request #22 from darxriggs/master

deferring creation of Asciidoctor instance to speedup task creation
Merge pull request #23 from melix/doclogging

Add a 'logDocuments' configuration option
close #24 after merging changes manually
Upgrade wrapper to Gradle 1.7
Fix broken build due to CodeNarc violations