hash_XXX<> classes already has template versions for
find() method. This patch adds templatized versions for
lower_bound, upper_bound, equal_range, and some other
more templatized methods in hash_XXX<> classes
Logged In: YES
Patch idear apply like the one for associative containers.
Only difference is that erase method is not template as it
conflicts with erase(const_iterator) overload.