Improve font search and handling on MS-Windows

Improve font search and handling on MS-Windows

* src/w32font.c: Add commentary about font search on MS-Windows.
(w32font_coverage_ok, add_font_entity_to_list)
(font_supported_scripts): Consider the coverage OK if a font has
only the SIP bit set, but also sets relevant codepage bits in the
CSB bits.
(font_supported_scripts): Fix script for USB bit 99.
* src/font.c (font_parse_fcname, font_parse_family_registry)
[HAVE_NTGUI]: Don't consider hyphenated suffixes of some Windows
fonts as not belonging to the family name.
* src/w32uniscribe.c (uniscribe_check_otf_1): Increase tags[]
array size, to avoid the E_OUTOFMEMORY error for some fonts.

* lisp/international/fontset.el (font-encoding-alist): Add
'unicode-sip'.

(cherry picked from commit ff6954b9c833bfeb8032fb772fa08e60e9ec56a8)