1) change poincare plot program's parameter dynamic_2_plots_headers into
dynamic_plots_headers
to allow draw many graps on a single plot

create a function
hra_math.utils.plot_utils.create_many_plots(_source_file, headers,
separator, window_size=None)
    which draws many plots base on data from _source_file and collection
of headers
    grouped by a semicolon, elements in a group are separated by a comma
in place of create_2_plots function

2) remove unnecessary function
hra_core.collections_utils.get_as_string(_iterarable)