HDB++

* Directory structure

  doc
     -> Documentation
  etc
     -> SQL for the creation of MySQL tables
  hdb++cm
     -> Configuration Manager Tango Device Server
  hdb++es
     -> Event Subscriber Tango Device Server
  libhdb++
     -> Abstraction library for DB interface
  libhdbmysql
     -> Implementation library for MySQL actual HDB interface
  libhdb++mysql
     -> Implementation library for MySQL new HDB++ interface

* Compilation

  hdb++es and hdb++cm needs to be compiled against libhdb++ and libhdbmysql
  to use actual hdb MySQL DB structure, or against libhdb++ and libhdb++mysql
  to use new sperimental MySQL DB structure.
  Set HDB++MYSQL = 0 in Make-hdb++.in in the first case, HDB++MYSQL = 1 in
  the second.

  Path adjustments:

  Makefiles refers to Make-hdb++.in and Make-8.1.2.c.in.
  In Make-hdb++.in adjust SQLIMPL_INC and SQLIMPL_LIB with MySQL paths,
  OMNI_INC and TANGO_INC with OmniORB and Tango include paths.
  In Make-8.1.2.c.in adjust TANGO_DIR and OMNIORB_DIR with Tango and
  OmniORB base paths.