RFR: 8074844 : Resolve disabled warnings for libfontmanager

[Philip Race]

Bug : https://bugs.openjdk.java.net/browse/JDK-8074844
Webrev : http://cr.openjdk.java.net/~prr/8074844/index.html

This resolves the disabled compiler warnings in what is now quite a 
small fontmanager library.

I've built windows, mac and linux in our build system and run our full 
battery of automated tests and sanity checked manual.

A quick run down of how the warnings map to the changes

       DISABLED_WARNINGS_clang := sign-compare,

       DISABLED_WARNINGS_gcc := sign-compare unused-function int-to-pointer-cast,

Sign compare in both of the above are the reason for the majority of the changes in freetypeScaler.c
and also the change in hb-jdk.h


unused-function was _free_nothing in
src/java.desktop/share/native/libfontmanager/hb-jdk-font.cc


int-to-pointer-cast was an issue for 32 bit as raised here https://bugs.openjdk.java.net/browse/JDK-8250605
when a previous removal broke 32 bit Linux. Since we don't build or test that I was flying in the dark here
using the warnings from that bug. The changes for this are those in

src/java.desktop/share/native/libfontmanager/DrawGlyphList.c
src/java.desktop/unix/native/libfontmanager/X11FontScaler.c


       DISABLED_WARNINGS_microsoft := 4018 4146 4244 4996,

The unique windows warnings were
./open/src/java.desktop/share/native/libfontmanager/HBShaper.c(216): error C2220: the following warning is treated as an error
  ./open/src/java.desktop/share/native/libfontmanager/HBShaper.c(216): warning C4244: '=': conversion from 'jlong' to 'long', possible loss of data

  ./open/src/java.desktop/share/native/libfontmanager/freetypeScaler.c(1216): error C2220: the following warning is treated as an error
  ./open/src/java.desktop/share/native/libfontmanager/freetypeScaler.c(1216): warning C4146: unary minus operator applied to unsigned type, result still unsigned

./open/src/java.desktop/windows/native/libfontmanager/lcdglyph.c(128): error C2220: the following warning is treated as an error
[ ./open/src/java.desktop/windows/native/libfontmanager/lcdglyph.c(128): warning C4996: 'GetVersion': was declared deprecated

GetVersion isn't needed any more since we aren't likely to be running on anything older than XP !

-phil.