Updates to 1.99A to Correct Issues for Linux and MacOSX

z88dk-src-1.99A has been updated to z88dk-src-1.99A-1
z88dk-osx-1.99A has been updated to z88dk-osx-1.99A-1

Issues Corrected:

z88dk/build.sh
grant execute permission

z88dk/libsrc/DEVELOPMENT/Makefile
prevent new c lib build from stopping on error while making the float library "m"

z88dk/libsrc/DEVELOPMENT/EXAMPLES/zx/demo_tritone/songs.asm
fix filename case issue

z88dk/libsrc/DEVELOPMENT/EXAMPLES/zx/demo_tritone/build.sh
added as counterpart of existing "Winmake.bat" for Windows