Makefile.sharedlibrary: mkdir in install target
Makefile.sharedlibrary: mkdir in install target

Headers are copied in $(INSTALL_PREFIX)/include so mkdir this directory
otherwise cp will fail
Same thing for libraries and $(INSTALL_PREFIX)/lib

Signed-off-by: Fabrice Fontaine <7d88633730b8b85c1516e612893df72eae9cd341@gmail.com>

svaarala/duktape,svaarala/duktape,svaarala/duktape,svaarala/duktape,svaarala/duktape,svaarala/duktape,svaarala/duktape,svaarala/duktape,svaarala/duktape