Add options 'configure --disable-SPKG' for standard packages

bootstrap

@@ -75,7 +75,19 @@ install_config_rpath() {
 bootstrap () {
     rm -f m4/sage_spkg_configures.m4
     spkg_configures=""
-    for filename in $(find build/pkgs -type f -name type); do
+    # --disable-SPKG options for standard packages
+    for filename in $(find build/pkgs -type f -name type | sort); do
+        pkgtype="$(cat $filename)"
+        pkgname="$(echo $filename | cut -d/ -f3)"
+        case "$pkgtype" in
+            standard)
+                spkg_configures="$spkg_configures
+SAGE_SPKG_ENABLE([$pkgname], [$pkgtype])"
+                ;;
+        esac
+    done
+    # --enable-SPKG options
+    for filename in $(find build/pkgs -type f -name type | sort); do
         pkgtype="$(cat $filename)"
         pkgname="$(echo $filename | cut -d/ -f3)"
         case "$pkgtype" in

m4/sage_spkg_enable.m4

@@ -1,15 +1,27 @@
 AC_DEFUN([SAGE_SPKG_ENABLE], [
   m4_pushdef([SPKG_NAME], [$1])
   m4_pushdef([SPKG_TYPE], [$2])
-  AC_ARG_ENABLE(SPKG_NAME,
+  m4_if(SPKG_TYPE, [standard], [
+    dnl standard packages; help message is deliberately very brief,
+    dnl as this is for advanced users only
+    AC_ARG_ENABLE(SPKG_NAME,
+      AS_HELP_STRING([--disable-]SPKG_NAME,
+                     [disable $2 package ]SPKG_NAME),
+      AS_VAR_SET(want_spkg, [$enableval]),
+      AS_VAR_SET(want_spkg, [yes])
+    )
+  ], [
+    dnl optional/experimental packages
+    AC_ARG_ENABLE(SPKG_NAME,
       AS_HELP_STRING([--enable-]SPKG_NAME={no|if_installed|yes},
                      [enable build and use of the $2 package ]SPKG_NAME[ (default: "if_installed")])
 AS_HELP_STRING([], [package information: ./sage -info ]SPKG_NAME)
 AS_HELP_STRING([--disable-]SPKG_NAME,
                      [disable build and uninstall if previously installed by Sage in PREFIX; same as --enable-]SPKG_NAME[=no]),
       AS_VAR_SET(want_spkg, [$enableval]),
       AS_VAR_SET(want_spkg, [if_installed])
-  )
+    )
+  ])
 
   AS_VAR_SET([is_installed], [no])
   for f in "$SAGE_SPKG_INST/SPKG_NAME"-*; do