Adds support to JSON parser in the nginx module

Building with --enable-standalone-module was failing due
the lack of the reference to the msc_json.c file inside the
standalone/Makefile.am. This patch also place the dependency
of the yajl to the nginx module config script.
Adds JSON support on ISS port

The JSON parse is already supported in Nginx and Apache
versions. This patch adds support on the IIS port.