[Mingw-cross-env-list] New package support for json-glib for MXE

[Johann Pfefferl]

Hello together,

I have integrated a glib based json package in the MXE development environment.
It would be nice if you can integrate this package into the official release.

I have not integrated an _UPDATE section because I am not completely sure what 
to provide there.

Thank you for this great cross dev environment,
  Johann
-- 
 -o)   A computer program does what you tell it to do,
 /\\        not what you want it to do.               
_\_v-

json-glib.mk
Description: Binary data

json-glib-test.c
Description: Text Data