Write all ranges of neighbouring characters with the same width using the range notat...

Write all ranges of neighbouring characters with the same width using the range notation in charmaps/UTF-8

Writing ranges of neighbouring characters with the same with like this

    <U000E0100>...<U000E01EF>	0

in charmaps/UTF-8 is more efficient than writing many single character lines
like:

    <U000E0100>	0
    <U000E0101>	0
    ...

	[BZ #21750]
	* unicode-gen/utf8_gen.py: Write all ranges of neighbouring characters
	with the same width using the range notation in charmaps/UTF-8.