Create /usr/local/include if it doesn't exist #275

Makefile

@@ -172,6 +172,8 @@ LDFLAGS_AS += -Wl,-install_name,lib${MQTTLIB_AS}.so.${MAJOR_VERSION} -L /usr/loc
 FLAGS_EXE += -DOSX
 FLAGS_EXES += -L /usr/local/opt/openssl/lib
 
+LDCONFIG = echo
+
 endif
 
 all: build
@@ -237,6 +239,7 @@ strip_options:
 install-strip: build strip_options install
 
 install: build
+	mkdir -p $(DESTDIR)$(PREFIX)${includedir}
 	$(INSTALL_DATA) ${INSTALL_OPTS} ${MQTTLIB_C_TARGET} $(DESTDIR)${libdir}
 	$(INSTALL_DATA) ${INSTALL_OPTS} ${MQTTLIB_CS_TARGET} $(DESTDIR)${libdir}
 	$(INSTALL_DATA) ${INSTALL_OPTS} ${MQTTLIB_A_TARGET} $(DESTDIR)${libdir}