As https://github.com/harfbuzz/harfbuzz/pull/1059#issuecomment-397912812 we
like to still work with blobs that harfbuzz itself can't handle directly that are failing sanitization
currently apparently.

This checks if the blob isn't empty and uses `hb_face_count`
to see if the font file passes the simple font file sanitization
so can detect if the input is actually a font and checks also
whether input font-index is out of range.

We were passing the font path directly to freetype so rendering
was broken when we are getting the font from stdin.

This fixes it by using FT_New_Memory_Face instead.

This fixes:
* build/util/hb-view /dev/stdin text < font.ttf
* build/util/hb-view - text < font.ttf
* cat font.ttf | build/util/hb-view - text

but doesn't work on
* cat font.ttf | build/util/hb-view /dev/stdin text

which I will try to fix separately.

Fixes https://github.com/harfbuzz/harfbuzz/issues/864

Unfortunately 1.7.7 and 1.8.0 went out with the wrong hb-version.h contents.

Just include hb-static.cc in libharfbuzz-subset.so source list as
well.  Those building it built-in will include hb-static.cc once
already.  No need for any gymnastics.

Fixes #1054.

Following to https://ci.appveyor.com/project/harfbuzz/harfbuzz/build/1.0.1693/job/mfkjdhcdykjuqdfc

Followup to https://github.com/harfbuzz/harfbuzz/pull/1053

New API:
+hb_set_is_subset()

Part of https://github.com/harfbuzz/harfbuzz/issues/630

This was causing problem on systems without visibility when map was used
from both libharfbuzz and libharfbuzz-subset. Sigh.

https://ci.appveyor.com/project/harfbuzz/harfbuzz/build/1.0.1669/job/dey47nmff0770vp3

Consonant_Initial_Postfixed was split off of Consonant_Succeeding_Repha,
so it should correspond to the same USE class, CONS_FINAL.

https://github.com/grigorig/ucdn/issues/19

UCDN is not updated yet.

Test suite results are unchanged (34).

I should've rebased #1002 before the merge, my bad

Simply, it returns the number of faces on a font blob.

To be used on hb-sanitizer tool but other clients also
can benefit from it.

Apparently this changed between Win 7 and Win 10.

Fixes https://github.com/harfbuzz/harfbuzz/issues/967

To be continued in https://github.com/harfbuzz/harfbuzz/issues/1044