updating versions

including removing snapshot dependency on wicketstuff-gmap3
Adding a demo app.

... a simplified version of the quickstart archetype, extended to
implement Locatable.
The extension itself has moved to the 'extension' directory.
Tidy-up, simplifying demo app.
fix to name in pom.xml
updated README, screenshosts, copyright.
Updated .travis.yml
Update to .gitignore
Updating to 1.4.0
updating scm to ssh
[maven-release-plugin] prepare release 1.4.0
[maven-release-plugin] prepare for next development iteration
Fix error in documentation
Refactoring to new structure (not yet complete, but compiles).
gmap3 now runs, still need to update package names and README.
Moving classes to correct package; deleting unused files; updating README.
Updated README, new screenshots
Fixing travis CI