Adding new database functionality to LDAP_NSS:

Create global context pointer (ent_context_t) for database type.

Create _nss_ldap_setXXXent and _nss_ldap_endXXXent fucntions.
Use same structure as similar funcitons for other DBs (use context pointer above)

Create global filter string object in ldap-schema.c
Create filter string in ldap-schema.c:_nss_ldap_init_filters()

Add an LM_XXX entry in the enumeration in ldap-nss.h (like LM_HOSTS).
Make sure you place it BEFORE LM_NONE. 
See ldap_map_selector_t variable (which is set to LM_HOSTS, etc) in 
_nss_ldap_search() for more info. Also see do_searchdescriptorconfig()

Add definition for ldap base of new db to util.h. eg: NSS_LDAP_KEY_NSS_BASE_ALIASES

**** Incomplete notes. Correctness of above is unknown ****