add Mac OS X support

use dylib shared lib extention
allow to specifiy os specific shared lib link option
Mac OS use -dynamiclib instead of -shared, -install_name instead of -soname
and does not support --version-script

add HOSTOS macro to detect the current os you are

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
1 file changed