build: Handle all programs names transformations

Previously only prepending a prefix was handled when installing 'crontab'.
Using the 'transform' Make macro allows the installation process to support
generic transformations as defined by the '--program-suffix' and
'--program-transform-name' configure options.

* configure.ac: Don't substitue '@real_program_prefix@'.
* Makefile.am (fpp): Remove.
(transform_exe): New macro.
[MULTI_USER] (install-exec-hook): Use it when installing 'crontab'.

Makefile.am

@@ -172,12 +172,13 @@ EXTRA_DIST = \
 ## Installation.  ##
 ## -------------- ##
 
-#full program prefix
-fpp = $(DESTDIR)$(bindir)/@real_program_prefix@
+# Sed command for Transforming program names.
+transform_exe = s/$(EXEEXT)$$//;$(transform);s/$$/$(EXEEXT)/
 
 if MULTI_USER
 install-exec-hook:
-	chmod u+s $(fpp)crontab$(EXEEXT)
+	tcrontab=`echo crontab$(EXEEXT) | sed '$(transform_exe)'`; \
+	chmod u+s $(DESTDIR)$(bindir)/$${tcrontab}
 endif
 
 ## --------------- ##

configure.ac

@@ -133,14 +133,6 @@ AC_ARG_WITH(tmp-dir,
 AC_MSG_RESULT($CONFIG_TMP_DIR)
 AC_SUBST(CONFIG_TMP_DIR)
 
-
-
-        
-# This is to support `make DESTDIR=...'
-                        
-real_program_prefix=`echo $program_prefix | sed s/NONE//`
-AC_SUBST(real_program_prefix)
-
 AC_CONFIG_FILES([pre-inst-env:build-aux/pre-inst-env.in],
   [chmod +x pre-inst-env])
 AC_CONFIG_FILES([doc/config.texi