Allow the C++ and swig client to request data at 16Hz from an nds2 server.
Passes FAST_STRIDE (-1) through to nds2 servers signaling the request for faster data if possible. On servers that do not support this it catches it as a command syntax error and reissues the request with AUTO_STRIDE.
Adds tests for C++ and Python.
Also adjusts the test program to do SO_REUSEADDR on its port so that it can be run by hand on the same port with back to back instances.
Closes #115 (closed)