Fixes #2

Position for initiation of a new damaged zone.

Added a new parameter: search_for_init_spacing_ratio, to control the position of new damaged zone resulting from the search for initiations process. Using this parameters, new damaged zone can only appear at a distance:

search_for_init_spacing_ratio*lc

to the already existing damaged zones.

Before that, the default arbitrary value was 0.125*lc. It was kept as a default value for search_for_init_spacing_ratio, so it should not change anything in the test cases.