Adding force->angstrom and force->qelectron to force.h and update.cpp for all unit systems. Not using these quantities all at, yet.

git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@7836 f3b2605a-c512-4ea7-a41b-209d697bcdaa

src/force.h

@@ -36,6 +36,8 @@ class Force : protected Pointers {
   double hhmrr2e;                    // conversion of (hbar)^2/(mr^2) to energy
   double mvh2r;                      // conversion of mv/hbar to distance 
                                      // hbar = h/(2*pi)
+  double angstrom;                   // 1 angstrom in native units
+  double qelectron;                  // 1 electron charge abs() in native units
 
   int newton,newton_pair,newton_bond;   // Newton's 3rd law settings