This is implementation of JIRA https://enyojs.atlassian.net/browse/ENYO-3638. The following is implemented:
- if an icon or a splash has no height/width specified, no such attribtue should be generated in config.xml
- we should only add a platform specific icon/splash element in `config.xml` if such a specific item has been selected by operator
- the `role` attribute is no longer needed/meaningful in `cordova.xml` therefore it is no longer generated.
Merge branch 'master' of github.com:enyojs/ares-project into ENYO-3638
Merge pull request #708 from enyojs/ENYO-3638

ENYO-3638: Config.xml: Remove default value on the height width images attributes