Add "float_warnings" patchsets for 1.9.3-p550, 1.9.3-p551, 2.0.0-p594, 2.0.0-p598  2.1.4 and 2.1.5
merge #3162: Add "float_warnings" patchsets for rubies
1.9.3-p550, 1.9.3-p551, 2.0.0-p594, 2.0.0-p598, 2.1.4 and 2.1.5