The HTTP request body is expected to be a valid JSON object. All other
requests are considered malformed requests and result in a HTTP 400 error.
Added the Jansson license to the LICENSE-THIRDPARTY.TXT file. Imported
some of the tests from the Jansson test suite to the HttpParser test.
Added find_package module for CMake which locates the Jansson libraries
and headers. This will make dependency checking easier and prevents build
failures due to missing dependencies.
