On disk format of directory   (xxx_dir.vpk. data is in xxx_000.vpk, xxx_001.vpk, ...)


id
records
 "extension\0"    (0 = no more extensions)
 "dir\0"          (0 = no more dirs)
   "basefilename\0" (0 = no more files of this extension in this dir)
   orig data file crc
   int16 metadata size
   location in data files for level 0 data (word filenum, ulong offset, ulong fsize)
   location in data files for level 1 data (word filenum, ulong offset, ulong fsize) ..
   -1.
   uint8 metadata[]

   
   ..
  ..
..

data files



[x]step0 - class def, format def
[x]step1 - generator
[x]step2 - loader
[ ]step3 - surrounding file monitor tools + ui



A client of the archive who can't handle their persistent meta data going away (as during
a reload) can say so, which will cuase their metadata to be copied away at next reload. otherwise,
a reload will change the address of the meta data and maybe its size/content.



insert

  case file found:
    find all files in the same data chunk
    load data chunk.
     replace old chunk of data, changing offsets in parts of files that were there.
	 replace offset and crc in old dir record
   case file not found
    might need to add new extension
    might need to add new directory
    insert new file entry
    add new data to last chunk
