Implement requested dynamic client capabilities.

* Implement a request to support loading clients from Couchbase doucments.
* Handles nested sections using new rlm_ldap code as an example.
* Complete Doxygen comments for all module structures and functions.
More eval debug messages
Remove extra debugging statement
If we're not escaping, pass \ straight thru
Allow for new escaping rules via a global variable
Use new escape variable in conditional parser
Use new escape when compiling "update" sections
Hacks to allow "correct_escapes"

We have to set it BEFORE we parse the rest of the config files,
which means we can't do it in a CONF_PARSERS.

So... it's a hack.  But an efficient one.
Use new escapes, and update tests
Allow section name2 to be parsed with correct escapes

Mainly for regexes in realms.  But also for "switch"
and "case" statements
Document new "correct_escapes" config item

And switch examples to using it.
The delimiter can be \\, too
correct example view and change strn* functions to use the strl* counterparts