Merge pull request #43 from PeterTonoli/dynamic-module

nginx-upload-progress-module can now be compiled as a dynamically loadable module

config

 ngx_addon_name=ngx_http_uploadprogress_module
-HTTP_FILTER_MODULES="$HTTP_FILTER_MODULES ngx_http_uploadprogress_module"
-NGX_ADDON_SRCS="$NGX_ADDON_SRCS $ngx_addon_dir/ngx_http_uploadprogress_module.c"
+if test -n "$ngx_module_link"; then
+    ngx_module_type=FILTER
+    ngx_module_name=ngx_http_uploadprogress_module
+    ngx_module_srcs="$ngx_addon_dir/ngx_http_uploadprogress_module.c"
+
+    . auto/module
+else
+    HTTP_FILTER_MODULES="$HTTP_FILTER_MODULES ngx_http_uploadprogress_module"
+    NGX_ADDON_SRCS="$NGX_ADDON_SRCS $ngx_addon_dir/ngx_http_uploadprogress_module.c"
+fi