Admin Guide configuration example confusion (ITS#691)

[cedric@earthling.net]

Full_Name: Cedric Tefft
Version: CVS
OS: N/A
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (205.138.230.84)


Yesterday's CVS version of the Admin Guide has a somewhat confusing example in
section 4.2: "Running configure" just after table 4.1: "Environment Variables". 
The verbage describing the example invocation of the configure script talks
about configuring the LDBM backend and the shell backend, but the shell backend
is not mentioned anywhere else in the example.  It is not clear how shell
support is being enabled.  If it is enabled by default this should be explicitly
stated so as not to confuse the reader.

Additionally, the given example enables a backend described as the "DNS-SRV"
backend which isn't mentioned anywhere else in the guide.