Conversion of the first of the mex functions to be octfile-compilable.

Not yet tested.
Now spinemlnetStop will octfile compile
spinemlnetQuery now compiles as octfile
Now all mex functions compile as octfiles
Fix fn name for spinenetGetData.cpp, and a comment. Have verified can send data into SpineCreator simulation now.
Corrects the get data code.
Ignore .oct output files
Adds a readme pertaining to the octbuild script
Additional info output
Fixes the get data function to actually return the data in the correct locations in the output matrix.
Merge branch 'oct_files'

The spinemlnet environment will now compile and work in Octave, though
there is one minor issue which I've not had time to resolve:

You can't run the environment twice without restarting octave.

The second time you run it, you get an EADDRINUSE error.

This is due to the fact that, although the code calls close()
successfully, as does the client part of the code (from
SpineML_2_BRAHMS), the lower level TCP/IP stack doesn't correctly shut
down the socket until octave exits. I don't yet know why this is; when
run from matlab it does.

A solution may be to rely on the client closing the connection, and
waiting until the connection really does close before closing and
exiting the spinemlnet env.