fix lattices, joint layout 7 + 13, arm topo guide

- fixed overly sized lattices. one vert at the head was selected too
when creating the lattice.
- added joint placements for char 7 and 13. build does not work without
problems yet. char7 gets eyes and shoulders offset from rivet (wtf?).
- added extras.ma to char folder
- found out what is wrong with the arm topology. characters are modelled
with all possibilities of right / left arm mixes. see guide for which
arm has which topo.