Add ZIP support

[bibendovsky]

Allow to store the assets inside ZIP archive file.

Conventions:

1. The following features of ZIP format are not supported:
   • ZIP64 extension
   • size of compressed or uncompressed data greater than 2147483647 bytes
   • compression methods other than store or deflate
   • any encryption
   • patched data
   • language related extra records
   • the archive splitted on multiple files
2. Archive file extension is .bstone_zip (i.e. my_data.bstone_zip).
3. File names starting with bstone are reserved (i.e. bstone_aog.bstone_zip).
4. Supported character set (sorted by the code points for convinience):
   • hyphen - (0x2D or 45)
   • period . (0x2E or 46)
   • numbers 0 to 9 (0x30-0x39 or 48-57)
   • underscore _ (0x5F or 95)
   • lowercase a to z (0x61-0x7A or 97-122)
5. The archive files in one directory adding to the search path in lexicographical order.
   Example
   • Unordered file names:
     • map2.bstone_zip
     • _sfx2.bstone_zip
     • map10.bstone_zip
     • -sfx2.bstone_zip
     • 7mus.bstone_zip
     • .sfx2.bstone_zip
     • 3mus51.bstone_zip
   • Ordered file names:
     • -sfx2.bstone_zip
     • .sfx2.bstone_zip
     • 3mus51.bstone_zip
     • 7mus.bstone_zip
     • _sfx2.bstone_zip
     • map10.bstone_zip
     • map2.bstone_zip