config: merge "Busybox Settings" and "Busybox Library Tuning" into one menu

Tweak a few help texts while at it

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/libbb/common_bufsiz.c b/libbb/common_bufsiz.c
index 2847eb5..f1124ba 100644
--- a/libbb/common_bufsiz.c
+++ b/libbb/common_bufsiz.c
@@ -19,6 +19,7 @@
 //config:
 //config:	  At link time, "text" is padded to a full page. At runtime, all "text"
 //config:	  pages are mapped RO and executable.
+//config:
 //config:	  "Data" starts on the next page boundary, but is not padded
 //config:	  to a full page at the end. "Bss" starts wherever "data" ends.
 //config:	  At runtime, "data" pages are mapped RW and they are file-backed