[perl #41870] [TODO] create config file processing library for use in pir

[Will Coleda via RT]

Done, but needs tests, and an example in the POD, like:

.sub main :main
  load_bytecode 'Config/JSON.pbc'
  .local pmc reader, writer
  reader = get_global [ 'Config' ; 'JSON' ], 'ReadConfig'
  writer = get_global [ 'Config' ; 'JSON' ], 'WriteConfig'

  .local pmc config  
  config = reader('foo.json')

  $P1 = new Hash
  $P1['stuff'] = 'this'
  $P1['other'] = 'that'

  config["supplemental"] = $P1

  writer(config, 'bar.json', 'compact'=>1)
.end