Feature fix small mistakes

* gemspec: required full texas (which is a problem when initially using the gem from source as dependencies are not available yet)
* PublishPDF
  * used `self.root` instead of `build.root`
  * couldn't determine page numbers for 1 page
* OpenPDF: used `CONFIG_FILE` instead of `Build::Base::CONFIG_FILE`
* Watch: overservered directories different from generated project structure.