Full Calendar newer version (post 2.1) does not replace properly previous version

FULLCAL-39 wasn't properly fixed.

The effect is that an extension that depends on fullcalendar version 2.0.2 does not see 2.1.7 as a replacement of 2.0.2.

More precisely:
The new version of the full calendar xar application, the macro-fullcalendar-ui should declare as features both macro-fullcalendar and vincentmassol:fullcalendar-application : the first one because that one used to be the ID of this extension until 2.1 (when it was split to ui and api) and the second one because it used to be a feature of the extension until 2.1.

I don't really understand why the commit for FULLCAL-39 https://github.com/xwiki-contrib/macro-fullcalendar/commit/d18a85a21781ffa05f591dd98d738ad1034a0471#diff-d0e9b0c0bf54289dc806b678e595eb94 replaces one id by the other when it should simply add it.

Note that this means to still keep the fix for FULLCAL-34 which is absolutely necessary as well for the whole management by extension manager to happen properly.