Rename editline.3 to libeditline.3 to avoid conflict with libedit

--- man/Makefile.in.orig	2020-02-23 17:55:52 UTC
+++ man/Makefile.in
@@ -270,7 +270,7 @@ top_build_prefix = @top_build_prefix@
 top_builddir = @top_builddir@
 top_srcdir = @top_srcdir@
 AUTOMAKE_OPTIONS = foreign
-dist_man_MANS = editline.3
+dist_man_MANS = libeditline.3
 all: all-am
 
 .SUFFIXES: