Dynamic modules. The auto/module script is extended to understand ngx_module_link=DYNAMIC. When set, it links the module as a shared object rather than statically into nginx binary. The module can later be loaded using the "load_module" directive. New auto/module parameter ngx_module_order allows to define module loading order in complex cases. By default the order is set based on ngx_module_type. 3rd party modules can be compiled dynamically using the --add-dynamic-module configure option, which will preset ngx_module_link to "DYNAMIC" before calling the module config script. Win32 support is rudimentary, and only works when using MinGW gcc (which is able to handle exports/imports automatically). In collaboration with Ruslan Ermilov.

--- a/auto/os/darwin
+++ b/auto/os/darwin
@@ -14,6 +14,9 @@ CORE_SRCS="$UNIX_SRCS $DARWIN_SRCS"
 ngx_spacer='
 '
 
+MAIN_LINK=
+MODULE_LINK="-shared -Wl,-undefined,dynamic_lookup"
+
 # kqueue
 
 echo " + kqueue found"