Let client response windows override init_delay

Allow client's response_window lower than main_config.init_delay to
override it. This allows initial request processing delay to track
client response windows, in addition to home server response windows.
Add max_response_timeouts option

Add "max_response_timeouts" - a home server option specifying number of
times replies are allowed to miss "response_window" before the server
enters the zombie period.

This allows more tolerance before transiting to zombie period for lower
response window configurations.
Make the configuration more understandable.  Fixes #678

It should just be "response_timeouts", and not "max_response_timeouts"
it's not an upper limit, and there's no "min" limit.

Setting "ignore this many replies missing" is hard to understand.
It's easier to say "trigger zombie period after response_timeouts
packets are lost".
Add sql_unset_user().  Fixes #640

It's really just a macro around pairdelete.  But it's clearer
to have sql_set_user() / sql_unset_user, than to use pairdelete
Update ChangeLog
Add support for dereferencing (following LDAP aliases)
Update ChangeLog
Fixed compile error in rlm_ldap
Fix radtest to work when the local hostname is not resolvable
Debug fixes for radeapclient
Fixup PG example and don't send application name by default
Shouldn't be an error...
Respect fr_hostname_lookups in libfreeradius
Remove empty debug message
Use correct lookup table. Fixes #686
Only parse dereference value if we actually have a value to parse
Remove 'children' option from rlm_ldap debug messages when the children scope is not available
Remove re-defined attributes
Fix and document check_timeout which helps with check_interval
Fixed some whitespace in mods-available/eap

Make consistently use of tabs, instead of mostly tabs and sometimes spaces.