Skill names are defined via 'defineskillname' as before, but the index
of the last non-empty skill name (plus one) is taken as the skill count.
So, if you only define the 6th, there will be no effect.
Note that currently, there is no way to specify less than four skills
because the CON parser doesn't allow the empty string for the name (it'll
go beyond the line) and because the default skill names are initialized in
EDuke32 too, in addition to the CONs.
git-svn-id: https://svn.eduke32.com/eduke32@2530 1a8010ca-5511-0410-912e-c29ae57300e0