TEveBoxSet classes:
Introduce new structure to draw cone set. 

tutorials/eve/boxset_test.C
Add function cone_test() to test cone set.

TEveDigitSet, TEveQuadSet:
Fix member in ERenderMode_e, to draw properly in wire-frame rendering mode.


git-svn-id: http://root.cern.ch/svn/root/trunk@24210 27541ba8-7e3a-0410-8455-c3a389f83636