Modified tests/runner to include herlpers
Modified conversions to include '*_from_m'

'from_m' is the mnemonic adopted for 'from MATLAB'
Modified util/socket to include custom conversion

- socket type from MATLAB
Modified util/sockopt to improve option lookup

- augmented with 'from_m' field ('from MATLAB' conversion function)
- custom conversions for mechanism also included
Added zmq_setsockopt
Included zmq_setsockopt in compile_list
Included test_zmq_setsockopt
Added m-file placeholder with little description for zmq_setsockopt