fixes issue 327 + relax assert on finding alloc routine module unload   b/c malloc_usable_size and _msize sometimes point   to same routine
fixes issue 327
+ relax assert on finding alloc routine module unload
  b/c malloc_usable_size and _msize sometimes point
  to same routine

git-svn-id: fe3cd4388a6e5a968b09397a3d721fe124e8117a@211 5b54908e-ead4-fc18-b48a-0285e6dbc711

rnk/drmemory,rnk/drmemory,rnk/drmemory,rnk/drmemory