Corrected implementation of ellipsoidal dynamics, made ashared base class for the time-integrators, templated the time-integrators (and so reversed changes that this PR had previously made to random_mars src files), combined docs of all three integrators.

src/random_mars.cpp

@@ -94,21 +94,6 @@ double RanMars::uniform()
   return uni;
 }
 
-/* ----------------------------------------------------------------------
-   uniform RN shifted to be symmetric about zero (for fix bd/sphere).
-------------------------------------------------------------------------- */
-double RanMars::uniform_middle()
-{
-  return uniform()-0.5;
-}
-
-/* ----------------------------------------------------------------------
-   Return 0 (for fix/bd/sphere).
-------------------------------------------------------------------------- */
-double RanMars::zero_rng()
-{
-  return 0.0;
-}
 
 /* ----------------------------------------------------------------------
    gaussian RN