Changed nntrain in the same way as rbmtrain so training until the error does not change anymore is possible now.
Furthermore I introduced a function to decide whether the code is run under Octave or Matlab. Based on that test, some optimisations are possible, so Octave's sumsq can and will be used now.
There is a function to initialise the options. It's a good place to comment all of them and maybe the examples can be reworked so that the option don't need to be initialised by hand all the time.