integrate USER-MOP package into build and documentat system. apply latest LAMMPS programming style conventions

We need "make no-lib" to be correct for automated testing to work, since only known packages with libraries can be successfully compiled through jenkins and other tools. Those scripts usually do "make yes-all no-lib" and then "make yes-XXX" for selected packages where it is known how to build the required libs.

through this change, the list of packages becomes accessible for the
library interface and the python wrapper, e.g. to check whether a
prerequisite packages is installed (simpler/faster for quick highlevel
check than having to try instantiating a specific style).

- remove feature to record the compilation time and date
- remove 'echo -n' based "progress bar"
- update output format for "lmp_machine -h" to be consistent with help output
- move generation of lmpinstalledpkgs.h to be a separate target depending on
  all sources and headers in src folder. this way it is only regenerated
  when files are modified or packages installed

give visual feedback on when the compile starts since gathering the package information can take time

changes to integrate USER-BOCS into LAMMPS and to closer follow the LAMMPS programming/documentation style

This reverts commit 4a3a6b44.
As it turns out, when using the LAMMPS python wrapper from inside
code using the PYTHON package, the library symbols *are* needed.
Thanks for Richard Berger (@rbberger) for pointing this out.

This reverts commit 4a3a6b44.
As it turns out, when using the LAMMPS python wrapper from inside
code using the PYTHON package, the library symbols *are* needed.
Thanks for Richard Berger (@rbberger) for pointing this out.

This reverts commit 4a3a6b44.
As it turns out, when using the LAMMPS python wrapper from inside
code using the PYTHON package, the library symbols *are* needed.
Thanks for Richard Berger (@rbberger) for pointing this out.

Step 1: very literal translation of lib/meam