[#2442] enable nitpicky in sphinx

To warn about all broken references. Also fixes the few broken
references found.

doc/sphinx/arm/config-backend.rst

@@ -241,8 +241,7 @@ servers.
 To differentiate between different Kea server configurations, a
 list of the server tags used by the servers must be stored in the
 database. For the DHCPv4 and DHCPv6 servers, it can be done using the
-:isccmd:`command-remote-server4-set` and
-:isccmd:`command-remote-server6-set` commands. The
+:isccmd:`remote-server4-set` and :isccmd:`remote-server6-set` commands. The
 server tags can then be used to associate the configuration information with
 the servers. However, it is important to note that some DHCP
 configuration elements may be associated with multiple server tags (known

doc/sphinx/arm/hooks-cb-cmds.rst

@@ -47,7 +47,7 @@ There are 5 types of commands supported by this library:
    :isccmd:`remote-global-parameter4-del`.
 
 -  ``get`` - fetch the selected object from the database, e.g.
-   :isccmd:`remote-subnet4-get`.
+   :isccmd:`remote-subnet4-get-by-id`.
 
 -  ``get-all`` - fetch all objects of the particular type from the
    database, e.g. :isccmd:`remote-option-def4-get-all`.

doc/sphinx/arm/logging.rst

@@ -263,8 +263,7 @@ libraries), or hook libraries (open source or premium).
    | ``kea-dhcp6.dhcp6``              |                                       |                                |
    +----------------------------------+---------------------------------------+--------------------------------+
    | ``kea-dhcp4.dhcpsrv``,           | core                                  | The base loggers for the       |
-   | ``kea-dhcp6.dhcpsrv``            |                                       | :ischooklib:`libkea-dhcpsrv`   |
-   |                                  |                                       | library.                       |
+   | ``kea-dhcp6.dhcpsrv``            |                                       | ``libkea-dhcpsrv.so`` library. |
    +----------------------------------+---------------------------------------+--------------------------------+
    | ``kea-dhcp4.eval``,              | core                                  | Used to log messages           |
    | ``kea-dhcp6.eval``               |                                       | relating to the                |
@@ -908,8 +907,8 @@ A complete list of logging parameters supported by Kea is shown in the table bel
    | ``%%``    | Outputs a literal percent sign                                         |
    +-----------+------------------------------------------------------------------------+
 
-Padding and truncation are also possible with modifiers preceeding the component.  This is 
-done by placing a number and other modifier characters between the component and the % 
+Padding and truncation are also possible with modifiers preceeding the component.  This is
+done by placing a number and other modifier characters between the component and the %
 sign. There are five ways of modifying the output shown by example here.
 
   - ``%20p``
@@ -934,7 +933,7 @@ sign. There are five ways of modifying the output shown by example here.
 
 Supported parameters depend on the liblog4cplus version used to compile Kea.  This can
 be checked by executing ``kea-dhcp4 -W | grep -i log4cplus`` which will produce output
-like this: ``LOG4CPLUS_VERSION:  2.0.5``.  Consult the documentation in the 
+like this: ``LOG4CPLUS_VERSION:  2.0.5``.  Consult the documentation in the
 `log4cplus wiki <https://github.com/log4cplus/log4cplus/wiki>`__ for further information
 about the version you have installed.
 

doc/sphinx/conf.py

@@ -125,6 +125,9 @@
     'arm/hooks-user-chk.rst',
 ]
 
+# Report broken references.
+nitpicky = True
+
 # Leave quotes and dashes unchanged and don't convert them to typographically
 # correct entities.
 smartquotes = False