Change AppConfig :report_page_size to :report_page_layout

* The AppConfig[:report_page_size] config variable was not used.
* Change AbstractReport#orientation method to AbstractReport#layout.
* AbstractReport#layout now returns AppConfig[:report_page_layout]
* Add a few extra comments to config-defaults.rb for info.
Merge pull request #13 from anarchivist/report-layout

Change AppConfig :report_page_size to :report_page_layout