enableSemantics no longer needed
Due to changes in how SMW is installed and initialized (now using Composer), enableSemantics() will still be used to ensure that NS related settings in LocalSettings still work the same as prior to SMW 1.9+Composer. For more information, see [1] and [2].
Pooh, things were indeed getting ugly here. :| I believe this should be included into the "INSTALL.md" before we embed this files content into this wiki. Thank you for keeping me in the loop on this!
James, can you please update the INSTALL.md file? You know best what the deal with the settings invocation is now.
I believe that indeed nothing has really changed except that SMW does not have to be invoked as before and that the $smwgNamespaceIndex parameter has to be set prior to enabling semantics as Daniel stated.