Code review comment for lp://staging/~posulliv/libmemcached/c++-interface

So I was thinking that when we actually port the memcached UDF's to Drizzle, we should use the libmemcached C++ interface since Drizzle is a C++ project. Thus, to enable that, I did some refactoring of the libmemcached C++ interface wrapper.

Basically, all I did was the following:

* replace parameters as char * with references to std::string
* use std::vector in places where arrays of pointers were being passed
* modified the return types of numerous API function to be bool instead of memcached_return
* added more test cases to the C++ API test file

I'm just proposing this for merging to get some feedback on the approach I've taken. I can easily keep the existing interface by just overloading those API functions if that is wanted.

-Padraig