vchoi_fork

[svn-r13076] 
fix for bugzilla bug #551

several programming errors contributed to this bug

1) the parsing of subsetting was using atoi to convert the parameter to an int,
which caused problems for numbers greater that int. Substitute with atof

2) several index counters were declared as int, use hsize_t instead

3) the numerical format passed for printf was %lu, defined one compatible with
hsize_t instead (unsigned long long)