Use reactor to find parent URL where possible patch (patch also includes improved calculate relative path and better read modules from filesystem POM functionality)

project.getParent().getUrl() returns non-interpolated values - using the reactor environment to locate the parent gives an interpolated url.

Additionally the patch includes a improved 'source the module details from the filesystem' functionality which is used in non-reactor environments, if a module is found not to define a URL (as it commonly doesnt as its inherited from parent) then the repository is queried instead.

Patch also includes a more powerful 'calculate realtive path' function that can handle divergent pathes share a common ancestor (e.g ../../../foo/bar/index.html) which is used to calculate parent and module hrefs.