Split LillyDAP into instance and class

[vanrein]

The current LillyDAP structure represents two things that ought to be split:

• structural class aspects, such as the API functions
• instance data aspects, such as the file handles

We should really split that, and make the instance data aspects reference the structural class aspects.

[vanrein]

The work to map previous code to the new data model is fairly simple:

• most calls use the data type LDAP or struct LillyConnection
• allocation is usually for the type LDAP or struct LillyConnection
• one (or more) static variable can be setup as LillyDAP or struct LillyStructural
  • it is therefore reset to 0 bytes
  • it should reference the opregistry, if any
  • it should setup the function stack in lillyget_xxx() and lillyput_xxx variables
  • it is linked from the def variable of any LDAP instance

[vanrein]

Implemented in 7ac7213