create branch v2.3.
add test codes for all types.
support void*
update libcstl version.
support void*
Merge branch 'v2.3' of https://github.com/activesys/libcstl into v2.3
support _Bool.
support long long and unsigned long long.
support range_t.
support basic_string_t.
support basic_string_iterator_t.
Optimization type.
Optimization of the iterator cycle performance.
Remove the array initialization for performance optimization.
update _type_hash.
delete some unit testing case.
Release libcstl-2.3.0.