Add Enlightenment to the Registered OnlyShowIn Environments

[Simon Lees]

Hi All,

As of the next Enlightenment release (e20) enlightenment will support 
the OnlyShowIn .desktop flag so it makes sense to add it to the list of 
registered environments. Currently the one spot using it uses 
X-Enlightenment so it makes sense to use the name "Enlightenment"

Cheers

Simon Lees

openSUSE Enlightenment Maintainer