BUG: Fix creation of string arrays from object types
STY: Formatting changes
ENH: vectorize boolean comparisons of floats

the new code will more often propagate the invalid floating point
exception if comparing against nan, so allclose now ignores it (but
still returns False)
Merge pull request #3507 from juliantaylor/vectorize-cmp

ENH: vectorize boolean comparisons of floats
Merge pull request #3491 from ContinuumIO/astype_fix2

Fix creation of string arrays from object types