Merge pull request #448 from imartinezortiz/pom-formatting

XML Formatting maven plugin
Removed some warnings from pom files
* list more extensions to ignore when checking licences
* fix a few duplicate dependencies in editor-core and desktop
Minor cosmetic cleanup in XMLFormatter
Merge pull request #450 from imartinezortiz/pom-formatting

Moving XMLFormatter mojo to its own maven artifact
Merge pull request #451 from manuel-freire/misc-improvements-to-poms

Misc improvements to poms
Removing skins from repository
Adding Generate skin atlas maven plugin

The maven plugin check if it is needed to generate the atlas (the target
location does not contain a generated skin's atlas) and generate it.
Fixes #253