Fixed bug.
Extended the parsing with ufloat_fromstr() to 12.3(NAN).
Added new officially parsed representations for ufloat_fromstr().
Fixed indentation.
Added tests for the new formats parsed by ufloat_fromstr().
Added test for additional representation.
Added parsing for one of the possibly outputs of format()--the one that distinguishes between an exact zero uncertainty and an approximate zero uncertainty.
Fixed test.
Extended numers_close() to NaN numbers.
Fixed test.
Fixed ambiguous format specification: "0.…" indicates either the use of zeroes in front of the number, or a zero width. This does not matter for floats, but matters for numbers with uncertainty, since a width triggers the duplicated exponent form, for the +/- format.
Fixed tests.
More precise comment.
Fixed test (related to the fact that in Python 2.7, '{:.1%}'.format(0.0055) is '0.5%'.