Rationalizations of the particle data toward multiple species

Remove from subroutines called by padvnc all reference to the
particle slot number. Use only the passed particle x_part data.

Changes to particle data storage in partcom.f and elsewhere:
Move the if_part information to an additional row x_part(iflag,i).
Remove all reference to if_part from whole code.
Move the dtprec information to additional row x_part(idtp,i).
Remove references to dtprec.
Remove the long obsolete iregion_part.
Add instead in common iic_part intended for list pointer.
Move charge assignment to padvnc

Removed mdims from padvnc, getadfield, setadfield arguments.
Add ndiags,psum,diagsum to padvnc argument list.
Put alternative call to achargetomesh into padvnc and
remove the chargetomesh call from the main loop.
Implement ispecies indexing of various controls etc.

E.g. npart, iocpart, iicpart, ninjcomp.
Also ensure that ion diagnostics and accumulation take place only for
ispecies.eq.1 which is ions.
Removed nplasdims references
Make cmdline handle multiple species.

Also remove mdims from ptaccom, and iasdims from mditcom.f
Fix ninjcalc, cinjinit, and cartreinject for multiple species

Removed Tneutral effectively from being used.
The effective value of vneutral is vd for all species but first.
Implement eoverms rather than rmtoz. Fix ninjcalc.

Pinit is (probably) finished for default electron second species.
First implementation of multiple particle species running.

Running with particle electrons demonstrated and elementary stability
boundary observed. Only the ion species is documented for flux,
but diagnostics are available for the higher species. The density
output is the total particle charge density. (True for Boltzmann electrons,
where it is the ion charge density. Boltzmann electrons aren't particles.)
RefManual needs updating, not yet done.
Corrections to RefManual and addressing gfortran compile
Make default numratio 1. Add -sp test to geometry.