ICC patch courtesy of John Jenkins.
Merge branch 'icc_support'
Added __cplusplus guards.
Fixed up some things C++ complains about:

Type-safe memory assignment was corrected in lots of places.
Put some typedef stuff AFTER its definition.
Corrected some complaints about TWOPT_END().
Merge branch 'cxx'

Now ROSS is able to be compiled with a C++ compiler (prior to this
commit, that had not been the case).
Changing to signed types.

This is to avoid problems that were detected by compiling and running
with clang 3.5 and the -fsanitize=integer flag.  The errors were:

/Users/laprej/ROSS/ross/gvt-mpi_allreduce.c:87:38: runtime error: unsigned integer overflow: 0 - 1 cannot be represented in type 'unsigned long long'
/Users/laprej/ROSS/ross/gvt-mpi_allreduce.c:87:38: runtime error: unsigned integer overflow: 17 - 20 cannot be represented in type 'unsigned long long'
Corrected the overflow bugs...