4.0.1 version bump

Author: stevengj

NEWS.md

@@ -1,5 +1,15 @@
 # Libctl Release Notes
 
+## libctl 4.0.1
+
+4/18/2018
+
+* Changed header file to use `const char *` rather than `char *`
+  for constant string arguments, since C++ deprecated passing
+  literal strings to `char *` arguments.
+
+* Various minor build and compilation improvements.
+
 ## libctl 4.0
 
 1/18/2018

configure.ac

@@ -1,5 +1,5 @@
 # Process this file with autoconf to produce a configure script.
-AC_INIT(libctl, 4.0.0, stevenj@alum.mit.edu)
+AC_INIT(libctl, 4.0.1, stevenj@alum.mit.edu)
 AC_CONFIG_SRCDIR([src/ctl.c])
 AC_CONFIG_HEADERS([config.h src/ctl.h])
 AC_CONFIG_MACRO_DIR([m4])