shells: do not frocibly enable test, echo and kill _applets_,

just build relevant source and use xxx_main functions.
build system: add a special case when we have exactly one applet enabled
(makes "true", "false", "basename" REALLY tiny).
getopt32: do not use stdio.

function                                             old     new   delta
getopt32                                            1385    1412     +27
make_device                                         1187    1200     +13
basename_main                                        120     127      +7
tcpudpsvd_main                                      1922    1926      +4
testcmd                                                5       -      -5
echocmd                                                5       -      -5
fuser_main                                          1243    1231     -12
------------------------------------------------------------------------------
(add/remove: 0/2 grow/shrink: 4/1 up/down: 51/-22)             Total: 29 bytes

1 files changed, 7 insertions, 2 deletions

diff --git a/applets/applet_tables.c b/applets/applet_tables.c
index 6c3492b4d..35b099eb4 100644
--- a/applets/applet_tables.c
+++ b/applets/applet_tables.c
@@ -69,9 +69,14 @@ int main(int argc, char **argv)
 
         /* Keep in sync with include/busybox.h! */
 
-        puts("/* This is a generated file, don't edit */");
+        puts("/* This is a generated file, don't edit */\n");
 
-        puts("const char applet_names[] ALIGN1 = \"\"\n");
+        if (NUM_APPLETS == 1) {
+                printf("#define SINGLE_APPLET_STR \"%s\"\n", applets[0].name);
+                printf("#define SINGLE_APPLET_MAIN %s_main\n\n", applets[0].name);
+        }
+
+        puts("const char applet_names[] ALIGN1 = \"\"");
         for (i = 0; i < NUM_APPLETS; i++) {
                 printf("\"%s\" \"\\0\"\n", applets[i].name);
         }