limit number of cubes for clump inertia integration scheme to 1000000; avoids worst case scenario with R_clump_member(s)<<R_clump
shorten code of Clump.cpp; improve inertia intergration scheme
undo unwanted changes in addToClump example from previous commit
bug fix of a previous commit
set maximum number of cubes for clump inertia integration scheme to 3375000 in Clump.cpp