Remove dependency on Java 1.7
Rename FileUtils methods, delete "allXmlFilesIn"
Clean up Dispatcher: make it actually dispatch.

- The `show` and `list` options are now in `LintRuleInformation`.
- The handling of the linting is now in `LintHandler`: it lints,
  reports, and exits if we're not in test mode. Previously, `Linter`s
  would create reports and exit, which was unusual.
- Test mode logic removed from LintFactory and moved into
  `LintRulesImpl`.
Add Javadoc documentation
Update to Gradle 1.11
Add rudimentary HTML report of current rules.

- Fixes #2.