Remove "$stylename = 'modern'"

It doesn't do anything, which is clearly evident from the fact that
the skin works correctly while the correct value would be 'Modern'.
See also I61c6e952 in core.

Change-Id: Ib05f21412e890bf30898d6fd0ea49ba97dbb49dc
Remove "$useHeadElement = true"

It doesn't do anything since I13e25cc8 in core.

Change-Id: I73c543e9120c81e4a654d2f083cc315215299f6a