Collected small fixes for the next patch release

Move pair style eam/cd from USER-MISC to MANYBODY

docs:  Fix spelling mistakes and clarify Tools.txt

emacs: Update mode file

changes to Packages and Speed doc files

Resolve object dependency problems for CMake build system

CMake updates

SPIN package fixes, especially for DMI

Coverity inspired fixes to BODY package

Also update the license and switch to GPL v2 like lammps

This is a squashed commit including the following changes:
1) Update mode header
2) Clean up white-space
3) Fix free variable warning
4) Add proper file ending stuff
5) Rename to keep conventional naming scheme
6) Updates to the readme
7) Update to conform to `package-lint` criteria
8) Add license header
9) Add in-file instructions

- improvements documentation (dmi and exchange)
- correction error cross product in pair_spin_dmi.cpp
- implementation mech. part in pair_spin_dmi.cpp
- correction in all pairs: init_one for [j][i] couples
- correction in atom_vec_spin.cpp: index error in read_data
- some improvements in pair_spin_dmi.cpp and pair_spin_magelec.cpp