Configure: honor dependencies of dynamic modules.

Dependencies of dynamic modules are added to NGX_ADDON_DEPS (and
it is now used for dynamic modules) to be in line with what happens
in case of static compilation.

To avoid duplication, MAIL_DEPS and STREAM_DEPS are no longer passed
to auto/module when these modules are compiled as dynamic ones.  Mail
and stream dependencies are handled explicitly via corresponding
variables.

auto/module

@@ -35,6 +35,10 @@ if [ "$ngx_module_link" = DYNAMIC ]; then
         CORE_INCS="$CORE_INCS $ngx_module_incs"
     fi
 
+    if test -n "$ngx_module_deps"; then
+        NGX_ADDON_DEPS="$NGX_ADDON_DEPS $ngx_module_deps"
+    fi
+
     libs=
     for lib in $ngx_module_libs
     do