Remove need for defining sgd/batch in exp_normal_n5p2.R

[dustinvtran]

sgd.R should be generic enough to work for all experiments.

[ptoulis]

Yes i think we need to have one code sgd.R for the SGD implementations
and one examples_main.R having generic code for the experiments --
the exp_* scripts should be a few lines long and should be there to let others run the experiments
quickly.

[dustinvtran]

run.all() in exp_poisson_n4p1.R is close to achieving that goal and will eventually be extended and placed into another file. There should also be more diagnostic functions aside from plot.risk(), such as a wrapper for performing time benchmarks.

[ptoulis]

Agreed. Let' s keep working on the other code, and eventually we will shape up the exp scripts
when the rest is finalized.

[dustinvtran]

e0b9cd2 cleans this as much as possible.