Tcl interfaces for adns, cdb, crypto, etc.

 Tcl bindings for:
  * adns (resolver library)
  * cdb (constant database) plus journalling writeable database
  * crypto: the nettle cryptographic library
  * hbytes: bytestrings with hex as string representation but efficient
 To make sensible use of these you will need a version of Tcl installed
 (this package is compatible with at least Tcl 8.0 to 8.4 inclusive).
 To use the adns and nettle bindings you need to have the
 appropriate libraries installed too.