Modify shms/mc_shms.f and shms/mc_shms_hut.f

shms/mc_shms.f
1) Set default use_coll flag to .true.

2) The array spec is used to keep the
x and y location of the particle at
each aperture in the SHMS. Moved the
filling of the array to before the
aperture check so that the positions
can be used if the particle fails the aperture
test.

In shms/mc_shms_hut.f

1) Changed the shmsSTOP_id values
 for the various checks in the
detector hut so that they do not
duplicate what is used in mc_shms.f