added customization to the function that streams data to file in order to later plot and reuse values at each step during optimization and until termination + example ref #51
updated main cmaes.h header in order to support plotting function customization, ref #51
fixed frequency of progress function output in progress function customization example code
Merge branch 'master' into nn_ex

Conflicts:
	examples/Makefile.am
	src/cmaes.h
	src/esostrategy.h