Import Unicode 12.0 data files

Import Unicode 12.0 data files

* admin/unidata/copyright.html:
* admin/unidata/UnicodeData.txt:
* admin/unidata/SpecialCasing.txt:
* admin/unidata/NormalizationTest.txt:
* admin/unidata/Blocks.txt:
* admin/unidata/BidiMirroring.txt:
* admin/unidata/BidiBrackets.txt: New versions from Unicode 12.0.
* admin/unidata/unidata-gen.el (unidata-gen-file):
* admin/unidata/blocks.awk (name2alias): Adapt to changes in
new data files.
* admin/notes/unicode: Update and improve instructions for
importing a new Unicode Standard.

* lisp/international/characters.el (char-width-table): Update
lists of characters according to Unicode 12.0.
* lisp/international/fontset.el (script-representative-chars):
Add characters from new scripts to 'script-representative-chars'.
(otf-script-alist): Update according to data on the MS site.
* lisp/international/mule-cmds.el (ucs-names): Update unused
ranges of codepoints according to Unicode 12.0.

* test/lisp/international/ucs-normalize-tests.el
(ucs-normalize-tests--failing-lines-part1)
(ucs-normalize-tests--failing-lines-part2): Update for the new
NormalizationTest.txt file.
* test/manual/BidiCharacterTest.txt: Update with the new
version from Unicode 12.0.