Investigate why InstalledFeatures is being ignored by XD packager

[marianopeck]

We created the UNIX.txt file by executing EmImageManager class>>#writePassiveImagePropertiesFor:

However, the InstalledFeatures list in the UNIX.txt is currently ignored. EmImageManager class>>#createNewImageWithPropertiesFrom: reads the lines from this file, but does not do anything with it. I cannot tell why. It looks like the code was removed at some point, or was forgotten to be added. So if you need to load features, you need to use the xdImage installFeatures: system. If you fixed EmImageManager class>>#createNewImageWithPropertiesFrom: to actually do the load from the UNIX.txt file, then there would be no need for the xdImage installFeatures: call in the abt.cnf.