Handle string length as size_t, consistently (almost always:))
Change function prototypes to accept size_t, where in the past
ulong or uint were used. change local/member variables to size_t
when appropriate.
This fix excludes rocksdb, spider,spider, sphinx and connect for now.
out of libmysql into separate dynamic plugins in the plugin/ directory.
move dialog and auth_socket plugins out of the plugin directory with examples into
dedicated directories in plugin/
