Add explicit support for being installed into a system triggered with --enable-fhs-paths.

Add two mechanism for avoiding name-collisions in a system-wide
installation of charybdis. The ssld and bandb daemons, intended to be
directly used by ircd and not the user, install into libexec when
--enable-fhs-paths is set. For binaries which are meant to be in PATH
(bindir), such as ircd and viconf, there is now an option
--with-program-prefix=progprefix inspired by automake. If the user
specifies --with-program-prefix=charybdis, the ircd binary is named
charybdisircd when installed.

Add support for saving the pidfile to a rundir and storing the ban
database in localstatedir instead of in sysconfdir. This is, again,
conditional on --enable-fhs-paths.

Fix(?) genssl.sh to always write created SSL key/certificate/dh
parameters to the sysconfdir specified during ./configure. The
previous behavior was to assume that the user ran genssl.sh after
ensuring that his current working directory was either sysconfdir or a
sibling directory of sysconfdir.

doc/Makefile.in

@@ -15,6 +15,8 @@ RM		= @RM@
 CP		= @CP@
 TOUCH		= @TOUCH@
 
+PROGRAM_PREFIX  = @PROGRAM_PREFIX@
+
 prefix		= @prefix@
 exec_prefix	= @exec_prefix@
 exec_suffix	= @exec_suffix@
@@ -73,8 +75,8 @@ install: install-mkdirs build
 
 	@echo "ircd: installing manpage"
 	@for i in $(MANPAGES); do \
-		if test ! -f $(DESTDIR)$(mandir)/$$i; then \
-			$(INSTALL_DATA) $$i $(DESTDIR)$(mandir); \
+		if test ! -f $(DESTDIR)$(mandir)/$(PROGRAM_PREFIX)$$i; then \
+			$(INSTALL_DATA) $$i $(DESTDIR)$(mandir)/$(PROGRAM_PREFIX)$$i; \
 		fi; \
 	done