use GNUInstallDirs from cmake to specify install paths.

Primarily this is to select whether 'lib64' or 'lib' is used on linux type systems.

ssl/CMakeLists.txt

@@ -60,8 +60,8 @@ if (BUILD_SHARED)
 		ARCHIVE_OUTPUT_NAME ssl${SSL_POSTFIX})
 	set_target_properties(ssl-shared PROPERTIES VERSION ${SSL_VERSION}
 		SOVERSION ${SSL_MAJOR_VERSION})
-	install(TARGETS ssl ssl-shared DESTINATION lib)
+	install(TARGETS ssl ssl-shared DESTINATION ${CMAKE_INSTALL_LIBDIR})
 else()
 	add_library(ssl STATIC ${SSL_SRC})
-	install(TARGETS ssl DESTINATION lib)
+	install(TARGETS ssl DESTINATION ${CMAKE_INSTALL_LIBDIR})
 endif()