Use compile-time paths in the manual pages

Replace the hard-coded paths for various BIND 9 files (configuration,
pid, etc.) in the man pages and ARM with compile-time values using the
sphinx-build replace system.

This is more complicated, because the restructured text specification
doesn't allow |substitions| inside ``code-blocks``, so for each specific
file we had to create own substition which is sub-optimal, but it is
only way how to do this without adding Sphinx extension.

(cherry picked from commit b42681c4e9)

Makefile.docs

@@ -9,6 +9,16 @@ AM_V_SPHINX_0 = @echo "  SPHINX   $@";
 
 SPHINXBUILDDIR = $(builddir)/_build
 
+LF = \n
+RNDC_CONF = .. |rndc_conf| replace:: ``$(sysconfdir)/rndc.conf``
+RNDC_KEY = .. |rndc_key| replace:: ``$(sysconfdir)/rndc.key``
+NAMED_CONF = .. |named_conf| replace:: ``$(sysconfdir)/named.conf``
+BIND_KEYS = .. |bind_keys| replace:: ``$(sysconfdir)/bind.keys``
+NAMED_PID = .. |named_pid| replace:: ``$(runstatedir)/named.pid``
+SESSION_KEY = .. |session_key| replace:: ``$(runstatedir)/session.key``
+
+export RST_EPILOG = $(RNDC_CONF)$(LF)$(RNDC_KEY)$(LF)$(NAMED_CONF)$(LF)$(BIND_KEYS)$(LF)$(NAMED_PID)$(LF)$(SESSION_KEY)
+
 common_SPHINXOPTS =			\
 	-W				\
 	-c $(srcdir)			\
@@ -17,18 +27,30 @@ common_SPHINXOPTS =			\
 
 # The "today" variable set below is not directly used in the ARM, but its value
 # is implicitly inserted on the title page of the PDF file produced by Sphinx.
-ALLSPHINXOPTS =				\
-	$(common_SPHINXOPTS)		\
-	-D today="$(RELEASE_DATE)"	\
-	$(SPHINXOPTS)			\
+ALLSPHINXOPTS =					\
+	$(common_SPHINXOPTS)			\
+	-D today="$(RELEASE_DATE)"		\
+	-D rst_epilog="$$(printf "$${RST_EPILOG}")"	\
+	$(SPHINXOPTS)				\
 	$(srcdir)
 
-man_SPHINXOPTS =			\
-	$(common_SPHINXOPTS)		\
-	-D version="@""PACKAGE_VERSION@"\
-	-D today="@""RELEASE_DATE@"	\
-	-D release="@""PACKAGE_VERSION@"\
-	$(SPHINXOPTS)			\
+_ = @
+man_RNDC_CONF = .. |rndc_conf| replace:: ``$(_)sysconfdir$(_)/rndc.conf``
+man_RNDC_KEY = .. |rndc_key| replace:: ``$(_)sysconfdir$(_)/rndc.key``
+man_NAMED_CONF = .. |named_conf| replace:: ``$(_)sysconfdir$(_)/named.conf``
+man_BIND_KEYS = .. |bind_keys| replace:: ``$(_)sysconfdir$(_)/bind.keys``
+man_NAMED_PID = .. |named_pid| replace:: ``$(_)runstatedir$(_)/named.pid``
+man_SESSION_KEY = .. |session_key| replace:: ``$(_)runstatedir$(_)/session.key``
+
+export man_RST_EPILOG = $(man_RNDC_CONF)$(LF)$(man_RNDC_KEY)$(LF)$(man_NAMED_CONF)$(LF)$(man_BIND_KEYS)$(LF)$(man_NAMED_PID)$(LF)$(man_SESSION_KEY)
+
+man_SPHINXOPTS =				\
+	$(common_SPHINXOPTS)			\
+	-D version="@""PACKAGE_VERSION@"	\
+	-D today="@""RELEASE_DATE@"		\
+	-D release="@""PACKAGE_VERSION@"	\
+	-D rst_epilog="$$(printf "$${man_RST_EPILOG}")"	\
+	$(SPHINXOPTS)				\
 	$(srcdir)
 
 AM_V_SED = $(AM_V_SED_@AM_V@)